Array Math

This example will demonstrate how to perform a mathematical operation between two input arrays for any given source.

This filter allows the user to select two input data arrays on which to perform math operations. The input arrays are used in their order of selection for the operations.

This example demos: PVGeo.filters.ArrayMath

import numpy as np
import pyvista

from PVGeo.filters import ArrayMath

Create some input data. This can be any vtkDataObject

inp = pyvista.ImageData(dimensions=(10, 10, 4))
# Populate the tables
n = 400
arr0 = np.random.random(n)
arr1 = np.random.random(n)
inp["Array 0"] = arr0
inp["Array 1"] = arr1

Use the filter:

f = ArrayMath(operation="add", new_name="foo")
# Now get the result
output = f.apply(inp, "Array 0", "Array 1")
output

Header	Data Arrays
ImageData Information N Cells 243 N Points 400 X Bounds 0.000e+00, 9.000e+00 Y Bounds 0.000e+00, 9.000e+00 Z Bounds 0.000e+00, 3.000e+00 Dimensions 10, 10, 4 Spacing 1.000e+00, 1.000e+00, 1.000e+00 N Arrays 3	Name Field Type N Comp Min Max Array 0 Points float64 1 2.346e-04 9.996e-01 Array 1 Points float64 1 1.743e-03 9.981e-01 foo Points float64 1 1.023e-01 1.937e+00

Note that the output now has three arrays

arr = output["foo"]
assert np.allclose(arr, arr0 + arr1)

Use a custom math operation:

def power(arr0, arr1):
    return arr0**arr1


# Use filter generated above
f.set_operation(power)
f.set_new_array_name("powered")
f.update()

# Now get the result
output = f.get_output()
output

Header	Data Arrays
ImageData Information N Cells 243 N Points 400 X Bounds 0.000e+00, 9.000e+00 Y Bounds 0.000e+00, 9.000e+00 Z Bounds 0.000e+00, 3.000e+00 Dimensions 10, 10, 4 Spacing 1.000e+00, 1.000e+00, 1.000e+00 N Arrays 3	Name Field Type N Comp Min Max Array 0 Points float64 1 2.346e-04 9.996e-01 Array 1 Points float64 1 1.743e-03 9.981e-01 powered Points float64 1 8.662e-03 1.000e+00

arr = output["powered"]
assert np.allclose(arr, arr0**arr1)

output.plot(scalars="powered")

Static Scene

Interactive Scene