Problems with GetRange()

ParaView Support
1

Dear community,
I use pvbatch-scripts to create images of my simulation results. I use the paraview version 5.7.0_mesa.
I want to get the range of an array I create with filters from the original arrays.
Here is an example:

def open_data(filename):
    data = pv.XDMFReader(FileNames=[filename])
    data.CellArrayStatus = ['velocity']
    return data

def get_y_velocity_range( file ) :
    data = open_data( file )
    calc = pv.Calculator( registrationName='x_calculator', Input=data )
    calc.ResultArrayName = 'y_velocity'
    calc.Function = 'velocity_Y'
    y_vel_range = calc.CellData.GetArray('y_velocity').GetRange()
    print( y_vel_range )
    pv.Delete( data )
    del data
    return calc

Whatever filter I use (in this example the Calculator), when I don’t use the GetRange()-function on an original array (in this example velocity), I get the following error message:

Traceback (most recent call last):
  File "../../range_example.py", line 43, in <module>
    Main()
  File "../../range_example.py", line 39, in Main
    get_y_velocity_range( f )
  File "../../range_example.py", line 21, in get_y_velocity_range
    y_vel_range = data.CellData.GetArray('y_velocity').GetRange()
AttributeError: 'NoneType' object has no attribute 'GetRange'

What am I doing wrong? From the message it seems to me, that the array ‘y_velocity’ does not exist. But I can display the results of calc in a RenderView, so this array has to exist.

2

Calculator creates PointData by default, try changing the AttributeType for the Calculator to CellData.

3

Thanks a lot, that worked for the calculator!

However, I have another questions:

Out of curiosity, I set the AttributeType to Point Data and changed the GetRange() command to y_vel_range = calc.PointData.GetArray('y_velocity').GetRange(). This gave me the error again. Why is that?

4

Once you set the AttributeType for the Calculator this means both the input and output would be of that type (cell or point). I assume your input is celldata so you’ll have to use that.
If you want to convert to point data, there is a filter that does that (cell data to point data).

Dan