# ArrayCalculator

Repository source: ArrayCalculator

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### Code¶

ArrayCalculator.py

#!/usr/bin/env python3

# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.util.data_model import vtkPolyData
from vtkmodules.vtkCommonCore import (
vtkPoints,
vtkDoubleArray
)
from vtkmodules.vtkCommonDataModel import vtkPolyData
from vtkmodules.vtkFiltersCore import vtkArrayCalculator

def main():
points = vtkPoints()
points.InsertNextPoint(1.0, 0.0, 0.0)
points.InsertNextPoint(2.0, 0.0, 0.0)
points.InsertNextPoint(3.0, 0.0, 0.0)

array = vtkDoubleArray(name='orig')
array.InsertNextValue(1.0)
array.InsertNextValue(2.0)
array.InsertNextValue(3.0)

polydata = vtkPolyData()
polydata.SetPoints(points)

calc1 = vtkArrayCalculator(input_data=polydata, result_array_name='orig', function='orig+1')
calc1.update()

output1 = calc1.GetPolyDataOutput().GetPointData().GetArray('orig')

print('output1 value = orig+1')
for i in range(0, output1.GetNumberOfTuples()):
print(f'  {i:2d}: {output1.GetValue(i):5.1f}')

calc2 = vtkArrayCalculator(input_data=polydata, result_array_name='new', function='if(orig=2,1,orig)')