[Paraview] Programmable filter issue with modifying grid data

[Burlen Loring]

Hi,

You haven't configured your output, assuming rectilinear grid you need 
to set the extent and provide coordinate arrays.

You are indexing a point based array with cell based index, so the 
lookup you make into vtkVarray is incorrect. 'Extent' tells you the 
number of cells, not the number of points, for that use 'Dimensions' or 
add one in each direction. Your script would certainly be more readable 
if you used some variables such as:

ncx = ext[1]-ext[0]+1
ncy = ext[3] -ext[2] +1
ncxy = nx*ny
ncz = ext[5]-ext[4] +1
cidx = k*nxy + j*nx+i

for number of cells and a cell array index.

In the two first loops you are treating 'i' as the slowest changing 
direction when it is the fastest. That will kill your performance. Last 
loop has correct order.

You may want to avoid the range function in your loop since if my 
recollection is correct that explicitly constructs a list of values.

I hope this is helpful.
Burlen

On 10/26/2011 10:41 PM, Mr FancyPants wrote:
> Hi there,
>
> I am trying to write a programmable filter which will take my 
> RectilinearGrid data and modify one of the data arrays. Specifically I 
> want to sum over one dimension. I have written something to do this, 
> but my data comes out garbled.
>
> Below is my code. Basically all I am doing is extracting all the data, 
> doing my sum over the z direction and then putting this data into 
> another rectilinear grid.
>
>
> *data=self.GetInput()*
> *out=self.GetOutput()*
> *extent=data.GetExtent()*
> *vtkVarray=data.GetPointData().GetArray('velocity')*
> *
> *
> *import numpy*
> *pyVarray_x = numpy.zeros([extent[1]+1,extent[3]+1,extent[5]+1])*
> *pyVarray_y = numpy.zeros([extent[1]+1,extent[3]+1,extent[5]+1])*
> *pyVarray_z = numpy.zeros([extent[1]+1,extent[3]+1,extent[5]+1])*
> *
> *
> *for i in range(0,extent[1]+1):*
> *for j in range(0,extent[3]+1):*
> *for k in range(0,extent[5]+1):*
> *tup=vtkVarray.GetTuple(i+j*(extent[1]+1)+k*(extent[1]+1)*(extent[3]+1))*
> *pyVarray_x[i,j,k]=tup[0]*
> *pyVarray_y[i,j,k]=tup[1]*
> *pyVarray_z[i,j,k]=tup[2]*
> *
> *
> *
> *
> *
> *
> *pyVarray_x_noz = numpy.zeros([extent[1]+1,extent[3]+1,1])*
> *pyVarray_y_noz = numpy.zeros([extent[1]+1,extent[3]+1,1])*
> *pyVarray_z_noz = numpy.zeros([extent[1]+1,extent[3]+1,1])*
> *
> *
> *for i in range(0,extent[1]+1):*
> *for j in range(0,extent[3]+1):*
> *pyVarray_x_noz[i,j]=pyVarray_x[i,j,:].sum()*
> *pyVarray_y_noz[i,j]=pyVarray_y[i,j,:].sum()*
> *pyVarray_z_noz[i,j]=pyVarray_z[i,j,:].sum()*
> *
> *
> *newArray=vtk.vtkDoubleArray()*
> *newArray.SetName("test")*
> *newArray.SetNumberOfComponents(3)*
> *
> *
> *print newArray*
> *
> *
> *for k in range(0,extent[5]+1):*
> *for j in range(0,extent[3]+1):*
> *for i in range(0,extent[1]+1):*
> *tup0=pyVarray_x_noz[i,j]*
> *tup1=pyVarray_y_noz[i,j]*
> *tup2=pyVarray_z_noz[i,j]*
> *tup=(tup0,tup1,tup2)*
> *newArray.InsertNextTuple((tup0,tup1,tup2))*
> *
> *
> *print newArray*
> *print vtkVarray*
> *
> *
> *out.GetCellData().AddArray(newArray)*
> *
> *
> I have no idea whats going wrong with this. Any help is much 
> appreciated, new to using paraview.
>
> Thanks, James
>
>
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