Transform: mesh transformation module
Preamble
Transform module performs simple transformations of meshes. It works on arrays (as defined in Converter documentation) or on CGNS/Python trees (pyTrees), if they provide grid coordinates. In the pyTree version, flow solution nodes and boundary conditions and grid connectivity are preserved if possible. In particular, splitting a mesh does not maintain the grid connectivity.
This module is part of Cassiopee, a free opensource pre and postprocessor for CFD simulations.
To use the module with the Converter.array interface:
import Transform as T
To use the module with the CGNS/Python interface:
import Transform.PyTree as T
List of functions
– Basic operations

Take one over N points from mesh. 

Reorder the numerotation of mesh. 

Orientate normals of all surface blocks consistently in one direction (1) or the opposite (1). 

Reorder a Cartesian mesh in order to get i,j,k aligned with X,Y,Z. 
Reorder a structured mesh to make it direct. 


Add N kplane(s) to a mesh. 
Collapse the smallest edge of each element for TRI arrays. 


Patch mesh2 defined by a2 in mesh1 defined by a1 at position (i,j,k). 
– Mesh positioning

Rotate a grid. 

Translate a grid. 
– Mesh transformation

Transform a mesh defined in Cartesian coordinates into cylindrical coordinates. 

Make for a mesh defined by an array an homothety of center Xc and of factor alpha. 

Contract a mesh around a plane defined by (center, dir1, dir2) and of factor alpha. 

Scale a mesh following factor (constant) or (f1,f2,f3) following dir. 

Make a symetry of mesh from plane passing by point and of director vector: vector1 and vector2. 

Perturbate a mesh randomly of radius Usage: perturbate(a, radius, dim) 

Smooth a mesh with a Laplacian. 

Smooth given fields. 

Returns the dual mesh of a conformal mesh. 
Break an array (in general NGON) in a set of arrays of BAR, TRI, … 
– Mesh splitting and merging

Take a subzone of mesh. 

Join two arrays in one or join a list of arrays in one. 

Merge a list of matching structured grids. 

Merge a list of Cartesian zones using the method of weakest descent. 

Split blocks in N blocks. 

Split a block until it has less than N points. 

Split a line following curvature angle. 

Return the indices of the array where the curvature radius is low. 
Split array into connex zones. 


Split any zone of A if it is connected to several blocks at a given border. 
Split all zones for matching on full faces. 


Split array into smooth zones (angles between elements are less than alphaRef). 

Split a BAR into a set of BARS at vertices where T branches exist. 

Split an unstructured mesh (only TRI or BAR currently) into several manifold pieces. 

Split BAR at index N (start 0). 

Split a TRI into several TRIs delimited by the input poly line defined by the lists of indices idxList. 
– Mesh deformation

Deform surface by moving surface of the vector dx, dy, dz. 

Deform a a surface of alpha times the surface normals. 

Deform mesh by moving point (x,y,z) of a vector (dx, dy, dz). 

Deform a mesh wrt surfDelta defining surface grids and deformation vector on it. 
– Mesh projections

Project points defined in arrays to surfaces according to the direction provided by vect. 

Project surfaces onto surface arrays following dir. 

Project a list of zones surfaces onto surface arrays following normals. 

Project a list of zones surfaces onto surface arrays following normals. 

Project surfaces onto surface arrays using rays starting from P. 
Contents
Basic operations

Transform.
oneovern
(a, (Ni, Nj, Nk)) Extract every Ni,Nj,Nk points in the three directions of a structured mesh a.
Exists also as an inplace version (_oneovern) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – input data
(Ni,Nj,Nk) (3tuple of integers) – period of extraction in the three directions
 Returns
a coarsened structured mesh
 Return type
identical to input
Example of use:
#  oneovern (array)  import Transform as T import Converter as C import Generator as G a = G.cart((0,0,0), (1,1,1), (10,10,1)) a2 = T.oneovern(a, (2,2,2)) C.convertArrays2File(a2, "out.plt")
#  oneovern (pyTree)  import Transform.PyTree as T import Converter.PyTree as C import Generator.PyTree as G a = G.cart((0,0,0), (1,1,1), (10,10,1)) a2 = T.oneovern(a, (2,2,1)); a2[0] = 'cart2' C.convertPyTree2File([a,a2], "out.cgns")

Transform.
reorder
(a, dest) For a structured grid, change the (i,j,k) ordering of a. If you set dest=(i2,j2,k2) for a (i,j,k) mesh, going along i2 direction of the resulting mesh will be equivalent to go along i direction of initial mesh.
The transformation can be equivalently described by a matrix M, filled with a single nonzero value per line and column (equal to 1 or 1). Then, dest=(desti,destj,destk) means: M[abs(desti),1]=sign(desti); M[abs(destj),2]=sign(destj); M[abs(destk),3]=sign(destk).
For an unstructured 2D grid (TRI, QUAD, 2D NGON), order the element nodes such that all normals are oriented towards the same direction. If dest is set to (1,), all elements are oriented as element 0. If dest is (1,), all elements are oriented in the opposite sense of element 0.
Exists also as an inplace version (_reorder) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – initial mesh
dest (3tuple of signed integers or a tuple of a single 1 or 1) – integers specifying transformation
 Returns
a reoriented mesh
 Return type
identical to input
Example of use:
#  reorder (array)  import Generator as G import Transform as T import Converter as C # Structured a = G.cart((0,0,0),(1,1,1),(5,7,9)) a = T.reorder(a, (3,2,1)) C.convertArrays2File(a, 'out1.plt') # Unstructured a = G.cartTetra((0,0,0),(1,1,1),(3,3,1)) a = T.reorder(a, (1,)) C.convertArrays2File(a, 'out2.plt')
#  reorder (pyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0,0,0), (1,1,1), (8,9,20)) a = T.reorder(a, (2,1,3)) C.convertPyTree2File(a, "out.cgns")

Transform.
reorderAll
(a, dir=1) Order a set of surface grids a such that their normals points in the same direction. All the grids in a must be of same nature (structured or unstructured). Orientation of the first grid in the list is used to reorder the other grids. If dir=1, the orientation is the opposite direction of the normals of the first grid.
In case of unstructured grids, reorientation is guaranteed to be outward (dir=1) if they represent a closed volume.
Exists also as an inplace version (_reorderAll) which modifies a and returns None.
 Parameters
a ([list of arrays] or [list of zones]) – initial set of surface grids
dir (signed integer) – 1 (default), 1 for a reversed orientation
 Returns
a reoriented mesh
 Return type
identical to input
Example of use:
#  reorderAll (array)  import Converter as C import Generator as G import Transform as T ni = 30; nj = 40 m1 = G.cart((0,0,0), (10./(ni1),10./(nj1),1), (ni,nj,1)) m2 = T.rotate(m1, (0.2,0.2,0.), (0.,0.,1.), 15.) m2 = T.reorder(m2,(1,2,3)) a = [m1,m2] a = T.reorderAll(a,1) C.convertArrays2File(a, "out.plt")
#  reorderAll (pyTree)  import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T ni = 30; nj = 40; nk = 1 m1 = G.cart((0,0,0), (10./(ni1),10./(nj1),1), (ni,nj,nk)); m1[0]='cart1' m2 = T.rotate(m1, (0.2,0.2,0.), (0.,0.,1.), 15.) m2 = T.reorder(m2,(1,2,3)); m2[0]='cart2' t = C.newPyTree(['Base',2,[m1,m2]]) t = T.reorderAll(t, 1) C.convertPyTree2File(t, "out.cgns")

Transform.
makeCartesianXYZ
(a) Reorder a structured Cartesian mesh in order to get i,j,k aligned with X,Y,Z respectively. Exists also as an inplace version (_makeCartesianXYZ) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – Cartesian mesh with (i,j,k) not ordered following (X,Y,Z)
 Returns
a Cartesian mesh such that direction i is aligned with (0X), …
 Return type
identical to input
Example of use:
#  makeCartesian(array)  import Generator as G import Transform as T import Converter as C a = G.cart((0.,0.,0.),(1.,1.,1.),(11,12,13)) a = T.reorder(a, (3,2,1)) a = T.makeCartesianXYZ(a) C.convertArrays2File(a, 'out.plt')
#  makeCartesian(pyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0.,0.,0.),(1.,1.,1.),(11,12,13)) a = T.reorder(a, (3,2,1)) a = T.makeCartesianXYZ(a) C.convertPyTree2File(a, 'out.cgns')

Transform.
makeDirect
(a) Reorder an indirect structured mesh to get a direct mesh. Exists also as an inplace version (_makeDirect) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – structured mesh
 Returns
a direct structured mesh
 Return type
identical to input
Example of use:
#  makeDirect (array)  import Generator as G import Transform as T import Converter as C a = G.cart((0.,0.,0.),(1.,1.,1.),(10,10,10)) a = T.reorder(a, (1,2,3)) # indirect now a = T.makeDirect(a) C.convertArrays2File(a, 'out.plt')
#  makeDirect (pyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0.,0.,0.),(1.,1.,1.),(10,10,10)) a = T.reorder(a, (1,2,3)) # indirect now a = T.makeDirect(a) C.convertPyTree2File(a, 'out.cgns')

Transform.
addkplane
(a, N=1) Add one or more planes at constant heights in z: z0+1, …,z0+N. Exists also as an inplace version (_addkplane) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – any mesh
N (integer) – number of layers in the k direction to be added
 Returns
expanded mesh
 Return type
identical to input
Example of use:
#  addkplane (array)  import Geom as D import Transform as T import Converter as C a = D.naca(12., 501) a = T.addkplane(a) C.convertArrays2File(a, "out.plt")
#  addkplane (pyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0.,0.,0.),(0.1,0.1,1.),(10,10,2)) a = T.addkplane(a) C.convertPyTree2File(a, 'out.cgns')

Transform.
collapse
(a) Collapse the smallest edges of each element of a triangular mesh. Return each element as a BAR. Exists also as an inplace version (_collapse) which modifies a and returns None.
 Parameters
a ([array list of arrays] or [zone, list of zones, base, pyTree]) – a TRI mesh
 Returns
a BAR mesh
 Return type
identical to input
Example of use:
#  collapse (array)  import Converter as C import Generator as G import Transform as T a = G.cartTetra((0.,0.,0.),(0.1,0.01,1.),(20,2,1)) b = T.collapse(a) C.convertArrays2File([a,b], "out.plt")
#  collapse (pyTree)  import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T a = G.cartTetra((0.,0.,0.),(0.1,0.01,1.),(20,2,1)) b = T.collapse(a) C.convertPyTree2File(b, "out.cgns")

Transform.
patch
(a, b, position=None, nodes=None, order=None) For a structured mesh a, patch (replace) a structured mesh b from starting point position=(i,j,k) of a. Coordinates and fields are replaced.
For an unstructured mesh a, patch an unstructured mesh (of same type) by replacing the nodes of indices nodes.
Exists also as an inplace version (_patch) which modifies a and returns None.
 Parameters
a (array or zone) – initial mesh
b (array or zone) – patch mesh
position (3tuple of integers) – indices starting from 1 of the starting node to be replaced in a
nodes (numpy array of integers (starting from 1)) – list of nodes of the unstructured mesh a to be replaced
order (None or 3tuple of integers) – 3tuple of integers indicating order of b relative to a (see reorder)
 Returns
a modified zone
 Return type
an array or a zone
Example of use:
#  patch (array)  import Transform as T import Generator as G import Converter as C import numpy c1 = G.cart((0,0,0), (0.01,0.01,1), (201,101,1)) c2 = G.cart((0,0,0), (0.01,0.01,1), (51,81,1)) c2 = T.rotate(c2, (0,0,0),(0,0,1),0.2) c3 = G.cart((0.0,1.,0), (0.01,0.01,1), (101,1,1)) c3 = T.rotate(c3, (0,0,0),(0,0,1),0.3) # patch a region at given position a = T.patch(c1, c2, position=(1,1,1)) # patch some nodes nodes = numpy.arange(20100, 20201, dtype=numpy.int32) b = T.patch(c1, c3, nodes=nodes) C.convertArrays2File([a,b], 'out.plt')
#  patch (pyTree)  import Transform.PyTree as T import Generator.PyTree as G import Converter.PyTree as C c1 = G.cart((0,0,0), (0.01,0.01,1), (201,101,1)) c2 = G.cart((0,0,0), (0.01,0.01,1), (51,81,1)) c2 = T.rotate(c2, (0,0,0),(0,0,1),0.2) a = T.patch(c1, c2, (1,1,1)) C.convertPyTree2File(a, 'out.cgns')
Mesh positioning

Transform.
rotate
(a, C, arg1, arg2=None, vectors=[['VelocityX','VelocityY','VelocityZ'],['MomentumX','MomentumY','MomentumZ']]) Rotate a mesh. Rotation can be also applied on some vector fields (e.g. velocity and momentum). If the vector field is located at cell centers, then each vector component name must be prefixed by ‘centers:’.
Exists also as an inplace version (_rotate) which modifies a and returns None.
Rotation parameters can be specified either by:
a rotation axis (arg1) and a rotation angle in degrees (arg2)
two axes (arg1 and arg2): axis arg1 is rotated into axis arg2
three Euler angles in degrees arg1=(alpha, beta, gamma). alpha is a rotation along X (Ox>Ox, Oy>Oy1, Oz>Oz1), beta is a rotation along Y (Ox1>Ox2, Oy1>Oy1, Oz1>Oz2), gamma is a rotation along Z (Ox2>Ox3, Oy2>Oy3, Oz2>Oz2):
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – mesh
C (3tuple of floats) – center of rotation
arg1 (3tuple of floats or 3tuple of 3tuple of floats) – rotation axis or original axis or rotation angles (in degrees)
arg2 (float or 3tuple of floats or None) – angle of rotation (in degrees) or destination axis or None
vectors ([list of list of strings]) – for each vector, list of the names of the vector components
 Returns
mesh after rotation
 Return type
identical to input
Example of use:
#  rotate (array)  import Generator as G import Transform as T import Converter as C a = G.cart((0,0,0), (1,1,1), (10,10,1)) # Rotate with an axis and an angle b = T.rotate(a, (0.,0.,0.), (0.,0.,1.), 30.) # Rotate with axis transformations c = T.rotate(a, (0.,0.,0.), ((1.,0.,0.),(0,1,0),(0,0,1)), ((1,1,0), (1,1,0), (0,0,1)) ) # Rotate with three angles d = T.rotate(a, (0.,0.,0.), (90.,0.,0.)) C.convertArrays2File([a,d], 'out.plt')
#  rotate (PyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0,0,0), (1,1,1), (10,10,2)) # Rotate with an axis and an angle b = T.rotate(a, (0.,0.,0.), (0.,0.,1.), 30.); b[0] = 'cartRot1' # Rotate with two axis c = T.rotate(a, (0.,0.,0.), ((1.,0.,0.),(0,1,0),(0,0,1)), ((1,1,0), (1,1,0), (0,0,1)) ); c[0] = 'cartRot2' # Rotate with three angles c = T.rotate(a, (0.,0.,0.), (0,0,90)); c[0] = 'cartRot3' C.convertPyTree2File([a,b,c], 'out.cgns')

Transform.
translate
(a, T) Translate a mesh of vector T=(tx,ty,tz).
Exists also as an inplace version (_translate) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – mesh
T (3tuple of floats) – translation vector
 Returns
mesh after translation
 Return type
identical to input
Example of use:
#  translate (array)  import Transform as T import Generator as G import Converter as C a = G.cart((0,0,0), (1,1,1), (10,10,1)) b = T.translate(a, (1.,0.,0.)) C.convertArrays2File([a,b], 'out.plt')
#  translate (pyTree)  import Transform.PyTree as T import Generator.PyTree as G import Converter.PyTree as C a = G.cart((0,0,0), (1,1,1), (10,10,3)) T._translate(a, (10.,0.,0.)) C.convertPyTree2File(a, 'out.cgns')
Mesh transformation

Transform.
cart2Cyl
(a, C, AXIS) Convert a mesh in Cartesian coordinates into a mesh in cylindrical coordinates. One of the Cartesian axes, defined by parameter AXIS, must be the revolution axis of the cylindrical frame. AXIS can be one of (0,0,1), (1,0,0) or (0,1,0).
Exists also as an inplace version (_cart2Cyl) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zone, base, pyTree]) – mesh with coordinates defined in the Cartesian frame
C (3tuple of floats) – center of revolution
AXIS (3tuple of floats) – revolution axis
 Returns
mesh with coordinates in the cylindrical frame
 Return type
identical to input
Example of use:
#  cart2Cyl (array)  import Transform as T import Generator as G import Converter as C a = G.cylinder((0.,0.,0.), 0.5, 1., 0., 360, 1., (360,20,10)) a = T.cart2Cyl(a, (0.,0.,0.),(0,0,1)) C.convertArrays2File(a, 'out.plt')
#  cart2Cyl (pyTree)  import Transform.PyTree as T import Generator.PyTree as G import Converter.PyTree as C a = G.cylinder((0.,0.,0.), 0.5, 1., 0., 360., 1., (360,20,10)) T._cart2Cyl(a, (0.,0.,0.),(0,0,1)) C.convertPyTree2File(a, 'out.cgns')

Transform.
homothety
(a, C, alpha) Apply an homothety of center C and a factor alpha to a mesh a.
Exists also as an inplace version (_homothety) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – mesh
C (3tuple of floats) – center of homothety
alpha (float) – homothety factor
 Returns
mesh after homothety
 Return type
identical to input
Example of use:
#  homothety (array)  import Generator as G import Transform as T import Converter as C a = G.cart((0,0,0), (1,1,1), (10,10,1)) b = T.homothety(a, (0.,0.,0.), 2.) C.convertArrays2File([a,b], 'out.plt')
#  homothety (PyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0,0,0), (1,1,1), (10,10,10)) b = T.homothety(a, (0.,0.,0.), 2.); b[0] = 'cart2' C.convertPyTree2File([a,b], "out.cgns")

Transform.
contract
(a, C, dir1, dir2, alpha) Make a contraction of factor alpha of a mesh with respect to a plane defined by a point C and vectors dir1 and dir2.
Exists also as an inplace version (_contract) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – mesh
C (3tuple of floats) – point of the contraction plane
dir1 (3tuple of floats) – first vector defining the plane
dir2 (3tuple of floats) – second vector defining the plane
alpha (float) – contraction factor
 Returns
mesh after contraction
 Return type
identical to input
Example of use:
#  contract (array)  import Generator as G import Transform as T import Converter as C a = G.cart((0,0,0), (1,1,1), (10,10,10)) b = T.contract(a, (0.,0.,0.), (1,0,0), (0,1,0), 0.1) C.convertArrays2File([a,b], 'out.plt')
#  contract (pytree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0,0,0), (1,1,1), (10,10,10)) b = T.contract(a, (0.,0.,0.), (1,0,0), (0,1,0), 0.1); b[0]='cart2' C.convertPyTree2File([a,b], 'out.cgns')

Transform.
scale
(a, factor=1., X=None) Scale a mesh of factor factor. If factor is a list of floats, scale with given factor for each canonical axis. If invariant reference point X is not given, it is set to the barycenter of a.
Exists also as an inplace version (_scale) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – mesh
factor (float or list of 3 floats) – scaling factor
X (None or tuple of 3 floats) – reference point
 Returns
mesh after scaling
 Return type
identical to input
Example of use:
#  scale (array)  import Transform as T import Generator as G import Converter as C a = G.cart((0,0,0), (1,1,1), (11,11,11)) # scale in all directions a = T.scale(a, factor=0.1) # scale in all directions with invariant point a = T.scale(a, factor=0.1, X=(0,0,0)) # scale with different factors following directions a = T.scale(a, factor=(0.1,0.2,0.3)) C.convertArrays2File(a, 'out.plt')
#  scale (pyTree)  import Transform.PyTree as T import Generator.PyTree as G import Converter.PyTree as C a = G.cart((0,0,0), (1,1,1), (11,11,11)) # scale in all directions T._scale(a, factor=0.1) # scale in all directions with a reference point T._scale(a, factor=0.1, X=(0,0,0)) # scale with different factors following directions T._scale(a, factor=(0.1,0.2,0.3)) C.convertPyTree2File(a, 'out.cgns')

Transform.
symetrize
(a, P, vector1, vector2) Symmetrize a mesh with respect to a plane defined by point P and vectors vector1 and vector2.
Exists also as an inplace version (_symetrize) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – mesh
C (3tuple of floats) – point of the symmetry plane
vector1 (3tuple of floats) – first vector of the symetry plane
vector2 (3tuple of floats) – second vector of the symetry plane
 Returns
mesh after symmetrization
 Return type
identical to input
Example of use:
#  symetrize (array)  import Generator as G import Transform as T import Converter as C a = G.cart((0,0,0), (1,1,1), (10,10,1)) # Symetrize regarding plane (x,z) b = T.symetrize(a, (0.,0.,0.), (1,0,0), (0,0,1)) C.convertArrays2File([a,b], "out.plt")
#  symetrize (PyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0,0,0), (1,1,1), (10,10,2)) # Symetrize regarding plane (x,z) b = T.symetrize(a, (0.,0.,0.), (1,0,0), (0,0,1)); b[0]='cart2' C.convertPyTree2File([a,b], "out.cgns")

Transform.
perturbate
(a, radius, dim=3) Perturbate randomly a mesh a with given radius. Mesh points are modified aleatoirely in all directions, with a distance less or equal to radius. If dim=2, Z coordinates are fixed. If dim=1, only the X coordinates are modified.
Exists also as an inplace version (_perturbate) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – mesh
radius (float) – radius of perturbation
dim (integer) – to select if 1, 2 or the 3 coordinates are modified.
 Returns
mesh after perturbation
 Return type
identical to input
Example of use:
#  perturbate (array)  import Generator as G import Transform as T import Converter as C a = G.cart((0,0,0), (1,1,1), (10,10,1)) a = T.perturbate(a, 0.1) C.convertArrays2File(a, "out.plt")
#  perturbate (PyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0,0,0), (1,1,1), (10,10,2)) b = T.perturbate(a, 0.1); b[0]='cart2' C.convertPyTree2File([a,b], "out.cgns")

Transform.
smooth
(a, eps=0.5, niter=4, type=0, fixedConstraints=[], projConstraints=[], delta=1., point=(0, 0, 0), radius=1.) Perform a Laplacian smoothing on a set of structured grids or an unstructured mesh (‘QUAD’, ‘TRI’) with a weight eps, and niter smoothing iterations. Type=0 means isotropic Laplacian, type=1 means scaled Laplacian, type=2 means taubin smoothing. Constraints can be defined in order to avoid smoothing of some points (for instance the exterior faces of a):
Exists also as an inplace version (_smooth) which modifies a and returns None.
 Parameters
a (array or zone) – input mesh
eps (float) – smoother power
niter (integer) – number of smoothing iterations
type (integer) – type of smoothing algorithm
fixedConstraints ([list of arrays] or [list of zones]) – set of fixed regions
projConstraints ([list of arrays] or [list of zones]) – smoothed mesh projected on them
delta (float) – strength of constraints
point (3tuple of float) – center of the region to be smoothed in case of local smoothing
radius (float) – if local smoothing, radius of the region to be smoothed
 Returns
mesh after smoothing
 Return type
array or zone
Example of use:
#  smooth (array)  import Transform as T import Converter as C import Geom as D a = D.sphere6((0,0,0), 1, N=20) b = T.smooth(a, eps=0.5, niter=20) C.convertArrays2File(a+b, "out.plt")
#  smooth (pyTree)  import Transform.PyTree as T import Geom.PyTree as D import Converter.PyTree as C a = D.sphere6((0,0,0), 1, N=20) b = T.smooth(a, eps=0.5, niter=20) C.convertPyTree2File(b, "out.cgns")

Transform.
smoothField
(a, eps=0.1, niter=1, type=0, varNames=[]) Perform a Laplacian smoothing on given fields.
Exists also as an inplace version (_smoothField) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – input zone with fields
eps (float) – smoother power
niter (integer) – number of smoothing iterations
type (integer) – type of smoothing algorithm
type – 0 (isotropic) or 1 (scale)
Example of use:
#  smoothField (array)  import Generator as G import Converter as C import Transform as T import numpy a = G.cartTetra((0,0,0), (1,1,1), (10,10,1)) a = C.initVars(a, '{ro}={x}') eps = 0.1; niter = 1; type = 0 #Transform.transform._smoothField(a, eps, None, niter, type, ['ro']) b = T.smoothField(a, eps, niter, type, ['ro']) T._smoothField(a, eps, niter, type, ['ro']) eps = numpy.empty( (C.getNPts(a)), dtype=numpy.float64) eps[:] = 0.1 T._smoothField(a, eps, niter, type, ['ro']) #Transform.transform._smoothField(a, 0., eps, niter, type, ['ro']) C.convertArrays2File(a, 'out.plt')
#  smoothField (pyTree)  import Generator.PyTree as G import Converter.PyTree as C import Transform.PyTree as T import numpy a = G.cartTetra((0,0,0), (1,1,1), (10,10,1)) a = C.initVars(a, '{Density}={CoordinateX}') eps = 0.1; niter = 1; type = 0 #b = T.smoothField(a, eps, niter, type, ['ro']) T._smoothField(a, eps, niter, type, ['Density']) eps = numpy.empty( (C.getNPts(a)), dtype=numpy.float64) eps[:] = 0.1 T._smoothField(a, eps, niter, type, ['Density']) C.convertPyTree2File(a, 'out.cgns')

Transform.
dual
(a, extraPoints=1) Return the dual of a mesh a. If extraPoints=1, external face centers are added.
Exists also as an inplace version (_dual) which modifies a and returns None.
 Parameters
a (array or zone) – mesh
extraPoints (integer) – 0/1 external face centers are added
 Returns
dual mesh
 Return type
array or zone
Example of use:
#  dual (arrays)  import Converter as C import Generator as G import Transform as T ni = 5; nj = 5; nk = 1 a = G.cart((0,0,0),(1,1,1),(ni,nj,nk)) a = C.convertArray2NGon(a); a = G.close(a) res = T.dual(a) C.convertArrays2File([res],'out.tp')
#  dual (pyTree) import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T ni = 5; nj = 5 a = G.cart((0,0,0),(1,1,1),(ni,nj,1)) a = C.convertArray2NGon(a); a = G.close(a) res = T.dual(a) C.convertPyTree2File(res, 'out.cgns')

Transform.
breakElements
(a) Break a NGON mesh into a set of grids, each of them being a basic element grid (with a single connectivity).
 Parameters
a (array or zone) – NGON mesh
 Returns
list of grids of basic elements
 Return type
[list of arrays or list of zones]
Example of use:
#  breakElements (array)  import Converter as C import Generator as G import Transform as T a = G.cartTetra((0,0,0),(1,1,1),(3,3,2)) a = C.convertArray2NGon(a) a = G.close(a) b = G.cartNGon((2,0,0),(1,1,1),(3,2,2)) res = T.join(a,b) res = T.breakElements(res) C.convertArrays2File(res, 'out.plt')
#  breakElements (pyTree)  import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T a = G.cartTetra((0,0,0),(1,1,1),(3,3,2)) a = C.convertArray2NGon(a) a = G.close(a) b = G.cartNGon((2,0,0),(1,1,1),(3,3,1)) res = T.join(a,b) res = T.breakElements(res) C.convertPyTree2File(res, 'out.cgns')
Mesh splitting and merging

Transform.
subzone
(a, minIndex, maxIndex=None, type=None) Extract a subzone.
Extract a subzone of a structured mesh a, where min and max ranges must be specified. Negative indices can be used (as in Python): 1 means max index:
b = T.subzone(a, (imin,jmin,kmin), (imax,jmax,kmax))
Extract a subzone of an unstructured mesh a, where the vertex list of the subzone must be specified (indices start at 1):
b = T.subzone(a, [1,2,...])
Extract a subzone of an unstructured mesh providing the indices of elements (index starts at 0):
b = T.subzone(a, [0,1,...], type='elements')
Extract a subzone of an unstructured array providing the indices of faces (for unstructured zones with basic elements: indFace=indElt*numberOfFaces+noFace, for NGON zones: use the natural face indexing, starting from 1):
b = T.subzone(a, [1,2,...], type='faces')
 Parameters
a (array or zone) – input data
minIndex (3tuple of integers) – (imin,jmin,kmin) for a structured grid, list of indices otherwise
maxIndex (3tuple of integers) – (imax,jmax,kmax) for a structured grid, None otherwise
type (None or string) – type of subzone to perform (None, ‘elements’, ‘faces’)
 Returns
subzoned mesh
 Return type
identical to a
Example of use:
#  subzone (array)  import Converter as C import Transform as T import Generator as G # Structure a = G.cart((0,0,0), (1,1,1), (10,20,10)) a = T.subzone(a, (3,3,3), (7,8,5)) # Structure avec indices negatif e = G.cart((0,0,0), (1,1,1), (10,20,10)) e = T.subzone(e, (1,1,1), (1,1,2)) # imax,jmax,kmax1 # Non structure. Indices de noeuds > retourne elts b = G.cartTetra((0,0,0), (1,1,1), (2,2,2)) b = T.subzone(b, [2,6,8,5]) # Non structure. Indices d'elements > Retourne elts # Les indices d'elements commencent a 0 c = G.cartTetra((0,0,0), (1,1,1), (5,5,5)) c = T.subzone(c, [0,1], type='elements') # Non structure. Indices de faces: # Pour les maillages BAR, TRI, TETRA... indFace=indElt*nbreFaces+noFace # les noFace commence a 1 # Pour les NGONS... indices des faces # > Retourne les faces d = G.cartTetra((0,0,0), (1,1,1), (2,2,2)) d = T.subzone(d, [1,2,3], type='faces') C.convertArrays2File([a,b,c,d,e], 'out.plt')
#  subzone (pyTree)  import Converter.PyTree as C import Transform.PyTree as T import Generator.PyTree as G a = G.cart((0,0,0), (1,1,1), (10,20,1)) a = T.subzone(a, (3,3,1), (7,8,1)) C.convertPyTree2File(a, 'out.cgns')

Transform.
join
(a, b=None, tol=1.e10) Join two zones in one (if possible) or join a list of zones in one zone (if possible). For the pyTree version, boundary conditions are maintained for structured grids only.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – input data
tol (float) – tolerance for abutting grids
 Returns
unique joined zone
 Return type
array or zone
Example of use:
#  join (array)  import Transform as T import Converter as C import Generator as G a1 = G.cartTetra((0.,0.,0.), (1.,1.,1), (11,11,1)) a2 = G.cartTetra((10.,0.,0.), (1.,1.,1), (10,10,1)) a = T.join(a1, a2) C.convertArrays2File([a], 'out.plt')
#  join (pyTree)  import Geom.PyTree as D import Transform.PyTree as T import Converter.PyTree as C a1 = D.naca(12., 5001) a2 = D.line((1.,0.,0.),(20.,0.,0.),5001) a = T.join(a1, a2) C.convertPyTree2File(a, "out.cgns")

Transform.
merge
(a, sizeMax=1000000000, dir=0, tol=1.e10, alphaRef=180., mergeBCs=False) Join a set of zones such that a minimum number of zones is obtained at the end. Parameter sizeMax defines the maximum size of merged grids. dir is the constraint direction along which the merging is prefered. Default value is 0 (no prefered direction), 1 for i, 2 for j, 3 for k. alphaRef can be used for surface grids and avoids merging adjacent zones sharing an angle deviating of alphaRef to 180.
For the pyTree version, boundary conditions are maintained for structured grids only.
 Parameters
a ([list of arrays] or [list of zones, base, pyTree]) – list of grids
sizeMax (integer) – maximum size of merged grids
dir (integer) – direction of merging (structured grids only): 0:ijk; 1:i; 2:j; 3:k
tol (float) – tolerance for abutting grids
alphaRef (float) – angle max of deviation for abutting grids, above which grids are not merged (for surface grids only)
mergeBCs (boolean) – if True, merge BCs and perform connectMatch
 Returns
list of merged grids
 Return type
[list of arrays] or [list of zones]
Example of use:
#  merge (array)  import Converter as C import Transform as T import Geom as D def f(t,u): x = t+u; y = t*t+1+u*u; z = u return (x,y,z) a = D.surface(f) b = T.splitSize(a, 100) b = T.merge(b) C.convertArrays2File(b, "out.plt")
#  merge (pyTree)  import Converter.PyTree as C import Transform.PyTree as T import Connector.PyTree as X import Geom.PyTree as D def f(t,u): x = t+u; y = t*t+1+u*u; z = u return (x,y,z) a = D.surface(f) b = T.splitSize(a, 100) b = X.connectMatch(b, dim=2) t = C.newPyTree(['Surface', b]) b = T.merge(t) t[2][1][2] = b C.convertPyTree2File(t, "out.cgns")

Transform.
mergeCart
(a, sizeMax=1000000000, tol=1.e10) Merge a set of Cartesian grids. This function is similar to the function Transform.merge but is optimized for Cartesian grids.
 Parameters
a ([list of arrays] or [list of zones, base, pyTree]) – list of Cartesian grids
sizeMax (integer) – maximum size of merged grids
tol (float) – tolerance for abutting grids
 Returns
list of merged Cartesian grids
 Return type
[list of arrays] or [list of zones]
Example of use:
#  mergeCart (array)  import Converter as C import Generator as G import Transform as T dh = 0.1; n = 11 A = [] a1 = G.cart((0.,0.,0.),(dh,dh,dh),(n,n,n)); A.append(a1) a2 = G.cart((1.,0.,0.),(dh,dh,dh),(n,n,n)); A.append(a2) a3 = G.cart((1.,1.,0.),(dh,dh,dh),(n,n,n)); A.append(a3) a4 = G.cart((0.,1.,0.),(dh,dh,dh),(n,n,n)); A.append(a4) A[0] = T.oneovern(A[0],(2,2,2)) A[1] = T.oneovern(A[1],(2,2,2)) res = T.mergeCart(A) C.convertArrays2File(res, "out.plt")
#  mergeCart (pyTree)  import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T dh = 0.1; n = 11 A = [] a1 = G.cart((0.,0.,0.),(dh,dh,dh),(n,n,n)); a1 = T.oneovern(a1,(2,2,2)) a2 = G.cart((1.,0.,0.),(dh,dh,dh),(n,n,n)); a2 = T.oneovern(a2,(2,2,2)) a3 = G.cart((1.,1.,0.),(dh,dh,dh),(n,n,n)) a4 = G.cart((0.,1.,0.),(dh,dh,dh),(n,n,n)) A = [a1,a2,a3,a4] for i in range(1,5): A[i1][0] = 'cart'+str(i) t = C.newPyTree(['Base']); t[2][1][2] += A t[2][1][2] = T.mergeCart(t[2][1][2]) C.convertPyTree2File(t, "out.cgns")

Transform.
splitNParts
(a, N, multigrid=0, dirs=[1,2,3], recoverBC=True, topTree=None) Split a set of M grids into N parts of same size roughly, provided M < N.
Argument multigrid enables to ensure the multigrid level by the splitting, provided the input grids are of that multigrid level. It can also be useful to split at nearmatch interfaces (multigrid=1 for 1:2 interfaces and multigrid 2 for 1:4 interfaces).
For the pyTree version, boundary conditions and matching connectivity are split.
Exists also as in place version (_splitNParts) that modifies a and returns None. In this case, a must be a pyTree.
 Parameters
a ([list of arrays] or [list of zones, base, pyTree]) – list of grids
N (integer) – number of grids after splitting
multigrid (integer) – for structured grids only. 0: no constraints; 1: grids are 2n+1 per direction ; 2: grids are 4n+1 per direction
dirs (list of integers (possible values:1,2,3 or a combination of them)) – directions where splitting is allowed (for structured grids only)
recoverBC (Boolean (True or False)) – BCs are recovered after split (True) or not (False)
topTree (CGNS Tree) – if a is not the top tree, provides full tree for match updates
 Returns
list of splitted grids
 Return type
[list of arrays] or [list of zones]
Example of use:
#  splitNParts (array)  import Generator as G import Transform as T import Converter as C a = G.cart((0,0,0), (1,1,1), (101,101,41)) b = G.cart((10,0,0), (1,1,1), (121,61,81)) c = G.cart((20,0,0), (1,1,1), (101,61,131)) res = T.splitNParts([a,b,c], 32, multigrid=0, dirs=[1,2,3]) C.convertArrays2File(res, 'out.plt')
#  splitNParts (pyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0,0,0), (1,1,1), (81,81,81)) b = G.cart((80,0,0), (1,1,1), (41,81,41)) t = C.newPyTree(['Base',a,b]) t = T.splitNParts(t, 10, multigrid=0, dirs=[1,2,3]) C.convertPyTree2File(t, 'out.cgns')

Transform.
splitSize
(a, N, multigrid=0, dirs=[1,2,3], type=0, R=None, minPtsPerDir=5, topTree=None) Split structured blocks if their number of points is greater than N.
splitSize can also be used to split blocks in order to fit as better as possible on a number of R processors.
Argument multigrid enables to ensure the multigrid level by the splitting, provided the input grids are of that multigrid level.
For the pyTree version, boundary conditions and matching connectivity are split.
Exists also as in place version (_splitSize) that modifies a and returns None. In this case, a must be a pyTree.
 Parameters
a ([list of arrays] or [list of zones, base, pyTree]) – list of grids
N (integer) – number of grids after splitting
multigrid (integer) – for structured grids only. 0: no constraints; 1: grids are 2n+1 per direction ; 2: grids are 4n+1 per direction
dirs (list of integers (possible values:1,2,3 or a combination of them)) – directions where splitting is allowed (for structured grids only)
type (integer) – only for split by size (not resources): 0: centered splitting; 1: upwind splitting when better
R (integer) – number of resources (processors)
minPtsPerDir (integer) – minimum number of points per direction
topTree (CGNS Tree) – if a is not the top tree, provides full tree for match updates
 Returns
list of splitted grids
 Return type
[list of arrays] or [list of zones]
Example of use:
#  splitSize (array)  import Generator as G import Transform as T import Converter as C a = G.cart((0,0,0),(1,1,1),(50,20,10)) B = T.splitSize(a, 2000, type=0) C.convertArrays2File(B, 'out.plt')
#  splitSize (pyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0,0,0),(1,1,1),(50,20,10)) t = C.newPyTree(['Base',a]) t = T.splitSize(t, 300, type=0) C.convertPyTree2File(t, 'out.cgns')

Transform.
splitCurvatureAngle
(a, sensibility) Split a curve defined by a 1D structured grid with respect to the curvature angle. If angle is lower than 180sensibility in degrees or greater than 180+sensibility degrees, curve is split.
 Parameters
a (array or zone) – list of grids
sensibility (float) – sensibility angle (in degrees) to allow splitting
 Returns
list of split curves
 Return type
[list of arrays] or [list of zones]
Example of use:
#  splitCurvatureAngle (array)  import Converter as C import Transform as T import Geom as D line = D.line((0.,0.,0.), (1.,1.,0.), 51) line2 = D.line((1.,1.,0.), (0.,0.,0.), 51) a = T.join(line2, line) list = T.splitCurvatureAngle(a, 30.) C.convertArrays2File(list, 'out.plt')
#  splitCurvatureAngle (pyTree)  import Converter.PyTree as C import Geom.PyTree as D import Transform.PyTree as T a = D.naca(12,101) a2 = D.line((1,0,0), (2,0,0), 50) a = T.join(a, a2) a2 = D.line((2,0,0), (1,0,0), 50) a = T.join(a, a2) zones = T.splitCurvatureAngle(a, 20.) C.convertPyTree2File(zones+[a], 'out.cgns')

Transform.
splitCurvatureRadius
(a, Rs=100.) Split a curve defined by a 1D structured grid with respect to the curvature radius, using BSpline approximations. The curve can be closed or not.
 Parameters
a (array or zone) – input mesh
Rs (float) – threshold curvature radius below which the initial curve is split
 Returns
list of split curves
 Return type
[list of arrays] or [list of zones]
Example of use:
#  splitCurvatureRadius (array)  import Converter as C import Transform as T import Geom as D pts = C.array('x,y,z', 7, 1, 1) x = pts[1][0]; y = pts[1][1]; z = pts[1][2] x[0]= 6.; x[1] = 5.4; x[2]=4.8; x[3] = 2.5; x[4] = 0.3 y[0]=10.; y[1]=0.036; y[2]=5.;y[3]=0.21;y[4]=0.26;y[5]=7. z[0]=1.; z[1]=1.; z[2]=1.;z[3]=1.;z[4]=1.;z[5]=1.; z[6]=1. a = D.bezier( pts, 50 ) L = T.splitCurvatureRadius(a) C.convertArrays2File([a]+L, 'out.plt')
#  splitCurvatureRadius (pyTree) import Converter.PyTree as C import Geom.PyTree as D import Transform.PyTree as T a = D.naca(12.5000) zones = T.splitCurvatureRadius(a, 10.) C.convertPyTree2File(zones+[a], 'out.cgns')

Transform.
splitConnexity
(a) Split an unstructured mesh into connex parts.
 Parameters
a (array or zone) – input unstructured mesh
 Returns
list of connex parts
 Return type
[list of arrays] or [list of zones]
Example of use:
#  splitConnexity (array)  import Converter as C import Transform as T import Geom as D a = D.text2D("CASSIOPEE") B = T.splitConnexity(a) C.convertArrays2File(B, 'out.plt')
#  splitConnexity (pyTree)  import Converter.PyTree as C import Transform.PyTree as T import Geom.PyTree as D a = D.text2D("CASSIOPEE") B = T.splitConnexity(a) C.convertPyTree2File(B, 'out.cgns')

Transform.
splitMultiplePts
(a, dim=3) Split a structured mesh at external nodes connected to an even number of points, meaning that the geometrical point connects an odd number of blocks.
 Parameters
a ([list of arrays] or [list of zones]) – input set of structured grids
 Returns
set of structured grids after splitting
 Return type
[list of arrays] or [list of zones]
Example of use:
#  splitMultiplePts (array)  import Generator as G import Transform as T import Converter as C z0 = G.cart((0.,0.,0.),(0.1,0.1,1.),(10,10,1)) z1 = T.subzone(z0,(1,1,1),(5,10,1)) z2 = T.subzone(z0,(5,1,1),(10,5,1)) z3 = T.subzone(z0,(5,5,1),(10,10,1)) zones = [z1,z2,z3] zones = T.splitMultiplePts(zones,dim=2) C.convertArrays2File(zones, 'out.plt')
#  splitMultiplePts (pyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C import Connector.PyTree as X nk = 2 z0 = G.cart((0.,0.,0.),(0.1,0.1,1.),(10,10,nk)) z1 = T.subzone(z0,(1,1,1),(5,10,nk)); z1[0] = 'cart1' z2 = T.subzone(z0,(5,1,1),(10,5,nk)); z2[0] = 'cart2' z3 = T.subzone(z0,(5,5,1),(10,10,nk)); z3[0] = 'cart3' z0 = T.translate(z0,(0.9,0.,0.)); z0[0] = 'cart0' z4 = G.cart((0.9,0.9,0.),(0.1,0.1,1.),(19,5,nk)); z4[0] = 'cart4' t = C.newPyTree(['Base',z1,z2,z3,z4]) t = X.connectMatch(t,dim=2) t = C.fillEmptyBCWith(t, 'wall', 'BCWall', dim=2) t = T.splitMultiplePts(t, dim=2) C.convertPyTree2File(t, 'out.cgns')

Transform.PyTree.
splitFullMatch
(a) Split a structured mesh such that all match boundaries are full block faces.
Exists also as in place version (_splitFullMatch) that modifies a and returns None. In this case, a must be a pyTree.
 Parameters
a ([pyTree, base or list of zones]) – input set of structured grids
 Returns
split zones
 Return type
identical to input
Example of use:
#  splitFullMatch (pyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C import Connector.PyTree as X z0 = G.cart((0.,0.,0.), (1,1,1), (10,10,1)) z1 = G.cart((0.,9.,0.),(1,1,1),(5,10,1)) z2 = G.cart((4.,9.,0.),(1,1,1),(6,10,1)) t = C.newPyTree(['Base',z0,z1,z2]) t = X.connectMatch(t, dim=2) T._splitFullMatch(t) C.convertPyTree2File(t, 'out.cgns')

Transform.
splitSharpEdges
(a, alphaRef=30.) Split a 1D or 2D mesh at edges sharper than alphaRef. If the input grid is structured, then it returns an unstructured grid (BAR or QUAD).
 Parameters
a ([array, list of arrays] or [zone, list of zones]) – input mesh
alphaRef (float) – angle (in degrees) below which the mesh must be split
 Returns
set of unstructured grids (with no sharp edges)
 Return type
[list of arrays] or [list of zones]
Example of use:
#  splitSharpEdges (array)  import Converter as C import Transform as T import Geom as D import Generator as G a = D.text3D("A"); a = G.close(a, 1.e4) B = T.splitSharpEdges(a, 89.) C.convertArrays2File(B, 'out.plt')
#  splitSharpEdges (pyTree)  import Converter.PyTree as C import Transform.PyTree as T import Geom.PyTree as D import Generator.PyTree as G a = D.text3D("A"); a = G.close(a, 1.e3) B = T.splitSharpEdges(a, 89.) C.convertPyTree2File(B, 'out.cgns')

Transform.
splitTBranches
(a, tol=1.e13) Split a curve defined by a ‘BAR’ if it has Tbranches.
 Parameters
a ([array, list of arrays] or [zone, list of zones]) – input mesh
tol (float) – matching tolerance between points that define two branches
 Returns
set of BAR grids (with no Tbranches)
 Return type
[list of arrays] or [list of zones]
Example of use:
#  splitTBranches (array) import Converter as C import Generator as G import Transform as T a = G.cylinder((0.,0.,0.), 0.5, 1., 360., 0., 10., (50,1,50)) c1 = T.subzone(a,(1,1,1),(50,1,1)) c2 = T.subzone(a,(1,1,50),(50,1,50)) c3 = T.subzone(a,(1,1,1),(1,1,50)) c = [c1,c2,c3]; c = C.convertArray2Hexa(c) c = T.join(c) res = T.splitTBranches(c) C.convertArrays2File(res,"out.plt")
#  splitTBranches (pyTree) import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T a = G.cylinder((0.,0.,0.), 0.5, 1., 360., 0., 10., (50,1,50)) c1 = T.subzone(a,(1,1,1),(50,1,1)) c2 = T.subzone(a,(1,50,1),(50,50,1)) c3 = T.subzone(a,(1,1,1),(1,50,1)) c = [c1,c2,c3]; c = C.convertArray2Hexa(c) c = T.join(c) res = T.splitTBranches(c) C.convertPyTree2File(res, "out.cgns")

Transform.
splitManifold
(a) Split a unstructured mesh (TRI or BAR only) into manifold pieces.
 Parameters
a ([array, list of arrays] or [zone, list of zones, base, pyTree]) – input mesh (TRI or BAR)
 Returns
set of TRI or BAR grids
 Return type
[list of arrays] or [list of zones]
Example of use:
#  splitManifold (array)  # Conforming 1 or 2 TRI/BAR together (same type for both operands import Converter as C import Generator as G import Intersector as XOR import Geom as D from Geom.Parametrics import base import Transform as T s1 = D.sphere( (0,0,0), 1, N=20 ) s2 = D.surface(base['plane'], N=30) s2 = T.translate(s2, (0.2,0.2,0.2)) s1 = C.convertArray2Tetra(s1); s1 = G.close(s1) s2 = C.convertArray2Tetra(s2); s2 = G.close(s2) x = XOR.conformUnstr(s1, s2, 0., 2) x = T.splitManifold(x) C.convertArrays2File(x, 'outS.plt') a = G.cylinder((0.,0.,0.), 0.5, 1., 360., 0., 10., (50,1,50)) c1 = T.subzone(a,(1,1,1),(50,1,1)) c2 = T.subzone(a,(1,1,50),(50,1,50)) c3 = T.subzone(a,(1,1,1),(1,1,50)) c = [c1,c2,c3]; c = C.convertArray2Hexa(c) c = T.join(c) C.convertArrays2File([c], 'B.plt') x = T.splitManifold(c) C.convertArrays2File(x, 'outB.plt')
#  conformUnstr (pyTree)  # Conforming 1 or 2 TRI/BAR together (same type for both operands import Converter.PyTree as C import Generator.PyTree as G import Intersector.PyTree as XOR import Geom.PyTree as D from Geom.Parametrics import base import Transform.PyTree as T s1 = D.sphere((0,0,0), 1, N=20) s2 = D.surface(base['plane'], N=30) s2 = T.translate(s2, (0.2,0.2,0.2)) s1 = C.convertArray2Tetra(s1); s1 = G.close(s1) s2 = C.convertArray2Tetra(s2); s2 = G.close(s2) x = XOR.conformUnstr(s1, s2, 0., 2) x = T.splitManifold(x) C.convertPyTree2File(x, 'outS.cgns') a = G.cylinder((0.,0.,0.), 0.5, 1., 360., 0., 10., (50,1,50)) c1 = T.subzone(a,(1,1,1),(50,1,1)) c2 = T.subzone(a,(1,50,1),(50,50,1)) c3 = T.subzone(a,(1,1,1),(1,50,1)) c = [c1,c2,c3]; c = C.convertArray2Hexa(c) c = T.join(c) x = T.splitManifold(c) C.convertPyTree2File(x, "outB.cgns")

Transform.
splitBAR
(a, N, N2=1) Split a curve defined by a BAR at index N. If N2 is provided, split also at index N2.
 Parameters
a (array or zone) – input mesh (BAR)
N (integer) – index of split in a
N2 (integer) – optional second split index
 Returns
two BARS
 Return type
[list of arrays] or [list of zones]
Example of use:
#  splitBAR (array)  import Generator as G import Converter as C import Transform as T a = G.cart((0,0,0), (1,1,1), (50,1,1)) a = C.convertArray2Tetra(a) b = T.splitBAR(a, 5) C.convertArrays2File(b, 'out.plt')
#  splitBAR (pyTree)  import Generator.PyTree as G import Converter.PyTree as C import Transform.PyTree as T a = G.cart((0,0,0), (1,1,1), (50,1,1)) a = C.convertArray2Tetra(a) B = T.splitBAR(a, 5) C.convertPyTree2File(B, 'out.cgns')

Transform.
splitTRI
(a, idxList) Split a triangular mesh into several triangular grids delineated by the polyline of indices idxList in the original TRI mesh.
 Parameters
a (array or zone) – input mesh (TRI)
idxList (list of integers) – indices of split in a defining a polyline
 Returns
a set of TRI grids
 Return type
[list of arrays] or [list of zones]
Example of use:
#  splitTRI (array)  import Generator as G import Converter as C import Transform as T a = G.cart((0,0,0),(1,1,1),(5,5,1)) a = C.convertArray2Tetra(a) C.convertArrays2File(a, 'out.plt') c = [[10,16,22], [2,8,9]] d = T.splitTRI(a, c) C.convertArrays2File(d[0], 'out1.plt') C.convertArrays2File(d[1], 'out2.plt')
#  splitTRI (PyTree)  import Generator.PyTree as G import Converter.PyTree as C import Geom.PyTree as D import Transform.PyTree as T a = D.circle( (0,0,0), 1, N=20 ) a = C.convertArray2Tetra(a) a = G.close(a) b = G.T3mesher2D(a) c = [[9, 25, 27, 30, 29, 28, 34, 38, 0], [29, 23, 19, 20, 24, 29]] D = T.splitTRI(b, c) C.convertPyTree2File(D, 'out.cgns')
Mesh deformation

Transform.
deform
(a, vector=['dx','dy','dz']) Deform a surface by moving each point of a vector. The vector field must be defined in a, with the same location.
Exists also as an inplace version (_deform) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones]) – input surface mesh, containing the vector fields
vector (list of 3 strings) – vector component names defined in a
 Returns
deformed surface mesh
 Return type
identical to input
Example of use:
#  deform (array)  import Converter as C import Generator as G import Geom as D import Transform as T a = D.sphere((0,0,0), 1., 50) n = G.getNormalMap(a) n = C.center2Node(n); n[1] = n[1]*10 a = C.addVars([a,n]) b = T.deform(a,['sx','sy','sz']) C.convertArrays2File([b], 'out.plt')
#  deform (pyTree)  import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T a = G.cart((0.,0.,0.),(1.,1.,1.),(10,10,10)) C._initVars(a,'dx', 10.) C._initVars(a,'dy', 0) C._initVars(a,'dz', 0) b = T.deform(a) C.convertPyTree2File(b, 'out.cgns')

Transform.
deformNormals
(a, alpha, niter=1) Deform a surface mesh a by moving each point of the surface by a scalar field alpha times the surface normals in niter steps
Exists also as an inplace version (_deformNormals) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones]) – input surface mesh, containing the vector fields
alpha (float) – factor of growth wrt to normals
niter (integer) – number of steps (raise it to increase the smoothing of the resulting surface)
 Returns
deformed surface mesh
 Return type
identical to input
Example of use:
#  deformNormals (array)  import Converter as C import Generator as G import Geom as D import Transform as T a = D.sphere((0,0,0), 1., 50) a = C.convertArray2Hexa(a) a = G.close(a) b = C.initVars(a, '{alpha}=0.5*{x}') b = C.extractVars(b, ['alpha']) b = T.deformNormals(a, b, niter=2) C.convertArrays2File([b], 'out.plt')
#  deformNormals (pyTree)  import Converter.PyTree as C import Geom.PyTree as D import Generator.PyTree as G import Transform.PyTree as T a = D.sphere6((0,0,0), 1., 10) a = C.convertArray2Hexa(a) a = T.join(a); a = G.close(a) a = C.initVars(a, '{alpha}=0.5*{CoordinateX}') a = T.deformNormals(a, 'alpha', niter=2) C.convertPyTree2File(a, 'out.cgns')

Transform.
deformPoint
(a, xyz, dxdydz, depth, width) Deform a surface mesh a by moving point P of vector V. Argument ‘depth’ controls the depth of deformation. Argument ‘width’ controls the width of deformation.
Exists also as an inplace version (_deformPoint) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones]) – input surface mesh, containing the vector fields
P (3tuple of floats) – point that is moved
V (3tuple of floats) – vector of deformation
depth (float) – to control the depth of deformation
width (float) – to control the width of deformation
 Returns
deformed surface mesh
 Return type
identical to input
Example of use:
#  deformPoint (array)  import Generator as G import Transform as T import Converter as C a1 = G.cart((0,0,0), (1,1,1), (10,10,1)) a2 = T.deformPoint(a1, (0,0,0), (0.1,0.1,0.1), 0.5, 2.) C.convertArrays2File([a2], "out.plt")
#  deformPoint (PyTree)  import Generator.PyTree as G import Transform.PyTree as T import Converter.PyTree as C a = G.cart((0,0,0), (1,1,1), (10,10,1)) a = T.deformPoint(a, (0,0,0), (0.1,0.1,1.), 0.5, 0.4) C.convertPyTree2File(a, "out.cgns")

Transform.
deformMesh
(a, surfDelta, beta=4., type='nearest') Deform a mesh defined by a given surface or a set of surfaces for which a deformation is defined at nodes as a vector field ‘dx,dy,dz’. The surface surfDelta does not necessary match with a border of the meshes. Beta enables to extend the deformation region as multiplication factor of local deformation.
Exists also as an inplace version (_deformMesh) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones]) – input surface mesh, containing the vector fields
surfDelta ([array,list of arrays] or [zone,list of zones]) – surface on which the deformation is defined
 Returns
deformed mesh
 Return type
identical to input
Example of use:
#  deformMesh (array)  import Transform as T import Converter as C import Geom as D a1 = D.sphere6((0,0,0), 1, 20) a1 = C.convertArray2Tetra(a1); a1 = T.join(a1) point = C.getValue(a1, 0) a2 = T.deformPoint(a1, point, (0.1,0.05,0.2), 0.5, 2.) delta = C.addVars(a1, ['dx','dy','dz']) delta = C.extractVars(delta, ['dx','dy','dz']) delta[1][:,:] = a2[1][:,:]a1[1][:,:] a1 = C.addVars([a1, delta]) m = D.sphere6((0,0,0), 2, 20) m = T.deformMesh(m, a1) C.convertArrays2File(m, "out.plt")
#  deformMesh (pyTree)  import Transform.PyTree as T import Converter.PyTree as C import Geom.PyTree as D a1 = D.sphere6((0,0,0),1,20) a1 = C.convertArray2Tetra(a1); a1 = T.join(a1) point = C.getValue(a1, 'GridCoordinates', 0) a2 = T.deformPoint(a1, point, (0.1,0.05,0.2), 0.5, 2.) delta = C.diffArrays(a2,a1) deltax = C.getField('DCoordinateX',delta) deltay = C.getField('DCoordinateY',delta) deltaz = C.getField('DCoordinateZ',delta) for noz in range(len(deltax)): deltax[noz][0] = 'dx' deltay[noz][0] = 'dy' deltaz[noz][0] = 'dz' a1 = C.setFields(deltax,a1,'nodes') a1 = C.setFields(deltay,a1,'nodes') a1 = C.setFields(deltaz,a1,'nodes') m = D.sphere6((0,0,0),2,20) m = T.deformMesh(m, a1) C.convertPyTree2File(m, "out.cgns")
Mesh projections

Transform.
projectAllDirs
(a, s, vect=['nx','ny','nz'], oriented=0) Project a surface mesh a onto a set of surfaces s according to a vector defined for each point of the mesh a. If oriented=0, both directions are used for projection, else the vector direction is used.
Exists also as an inplace version (_projectAllDirs) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones]) – input surface mesh, containing the vector fields
s ([array,list of arrays] or [zone,list of zones]) – projection surface
vect (list of 3 strings) – vector component names
oriented (integer (0 or 1)) – 0 for projection in the vector direction and also in its opposite direction
 Returns
projected mesh
 Return type
identical to input
Example of use:
#  projectAllDirs (array)  import Geom as D import Converter as C import Generator as G import Transform as T a = D.sphere6((0,0,0), 1., 20) b = G.cart((1.1,0.1,0.1),(0.03,0.03,0.03), (1,50,50)) n = G.getNormalMap(b) n = C.center2Node(n) b = C.addVars([b,n]) c = T.projectAllDirs([b], a, ['sx','sy','sz']) C.convertArrays2File([b]+c, 'out.plt')
#  projectAllDirs (pyTree)  import Geom.PyTree as D import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T a = D.sphere((0,0,0), 1., 20) b = G.cart((1.1,0.1,0.1),(0.1,0.1,0.1), (1,5,5)) b = G.getNormalMap(b) b = C.center2Node(b,['centers:sx','centers:sy','centers:sz']) c = T.projectAllDirs(b, a,['sx','sy','sz']); c[0] = 'projection' C.convertPyTree2File([a,b,c], 'out.cgns')

Transform.
projectDir
(a, s, dir, smooth=0, oriented=0) Project a surface mesh a onto a set of surfaces s following a constant direction dir. If oriented=0, both directions are used for projection, else the vector direction is used. If smooth=1, points that cannot be projected are smoothed (available only for structured grids).
Exists also as an inplace version (_projectDir) which modifies a and returns None.
 Parameters
a ([array list of arrays] or [zone, list of zones]) – input surface mesh
s ([array, list of arrays] or [zone, list of zones]) – projection surface
dir (3tuple of floats) – constant vector that directs the projection
smooth (integer (0 or 1)) – smoothing of unprojected points
oriented (integer (0 or 1)) – 0 for projection in the vector direction and also in its opposite direction
 Returns
projected mesh
 Return type
identical to input
Example of use:
#  projectDir (array)  import Geom as D import Converter as C import Generator as G import Transform as T a = D.sphere((0,0,0), 1., 20) b = G.cart((1.1,0.1,0.1),(0.03,0.03,0.03), (1,50,50)) c = T.projectDir(b, [a], (1.,0,0)) d = T.projectDir([b], [a], (1.,0,0), smooth=1) C.convertArrays2File([a,b,c]+d, 'out.plt')
#  projectDir (pyTree)  import Geom.PyTree as D import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T a = D.sphere((0,0,0), 1., 20) b = G.cart((1.1,0.1,0.1),(0.1,0.1,0.1), (1,5,5)) c = T.projectDir(b, a, (1.,0,0)); c[0] = 'projection' C.convertPyTree2File([a,b,c], 'out.cgns')

Transform.
projectOrtho
(a, s) Project a surface mesh a orthogonally onto a set of surfaces s.
Exists also as an inplace version (_projectOrtho) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones]) – input surface mesh, containing the vector fields
s ([array, list of arrays] or [zone, list of zones]) – projection surface
 Returns
projected mesh
 Return type
identical to input
Example of use:
#  projectOrtho (array)  import Geom as D import Converter as C import Generator as G import Transform as T a = D.sphere((0,0,0), 1., 300) b = G.cart((0.5,0.5,1.5),(0.05,0.05,0.1), (20,20,1)) c = T.projectOrtho(b, [a]) C.convertArrays2File([a,b,c], 'out.plt')
#  projectOrtho (pyTree)  import Geom.PyTree as D import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T a = D.sphere((0,0,0), 1., 20) b = G.cart((1.1,0.1,0.1),(0.1,0.1,0.1), (1,5,5)) c = T.projectOrtho(b, a); c[0] = 'projection' C.convertPyTree2File([a,b,c], 'out.cgns')

Transform.
projectOrthoSmooth
(a, s, niter=1) Project a surface mesh a following smoothed normals onto a set of surfaces s.
Exists also as an inplace version (_projectOrthoSmooth) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones]) – input surface mesh
s ([array, list of arrays] or [zone, list of zones]) – projection surface
niter (integer) – number of smoothing iterations
 Returns
projected mesh
 Return type
identical to input
Example of use:
#  projectOrthoSmooth (array)  import Geom as D import Converter as C import Generator as G import Transform as T a = D.sphere((0,0,0), 1., 30) b = G.cart((0.5,0.5,1.5),(0.05,0.05,0.1), (20,20,1)) c = T.projectOrthoSmooth(b, [a], niter=2) C.convertArrays2File([a,b,c], 'out.plt')
#  projectOrthoSmooth (pyTree)  import Geom.PyTree as D import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T a = D.sphere((0,0,0), 1., 30) b = G.cart((0.5,0.5,1.5),(0.05,0.05,0.1), (20,20,1)) c = T.projectOrthoSmooth(b, [a], niter=2) C.convertPyTree2File([a,b,c], 'out.cgns')

Transform.
projectRay
(a, s, P) Project a surface mesh a onto a set of surfaces s following rays starting from a point P.
Exists also as an inplace version (_projectRay) which modifies a and returns None.
 Parameters
a ([array, list of arrays] or [zone, list of zones]) – input surface mesh
s ([array, list of arrays] or [zone, list of zones]) – projection surface
P (3tuple of floats) – starting point of rays
 Returns
projected mesh
 Return type
identical to input
Example of use:
#  projectRay (array)  import Geom as D import Converter as C import Generator as G import Transform as T a = D.sphere((0,0,0), 1., 20) b = G.cart((1.1,0.1,0.1),(0.1,0.1,0.1), (1,5,5)) c = T.projectRay(b, a, (0,0,0)) C.convertArrays2File([a,b,c], 'out.plt')
#  projectRay (pyTree)  import Geom.PyTree as D import Converter.PyTree as C import Generator.PyTree as G import Transform.PyTree as T a = D.sphere((0,0,0), 1., 20) b = G.cart((1.1,0.1,0.1),(0.1,0.1,0.1), (1,5,5)) c = T.projectRay(b, a, (0,0,0)); c[0] = 'projection' C.convertPyTree2File([a,b,c], 'out.cgns')