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Invert a Mosel matrix with NumPy


Type: Programming
Rating: 2 (easy-medium)
Description: Invert a Mosel matrix in Python using NumPy.
File(s): invert_matrix.mos
Data file(s): invert_matrix.py


invert_matrix.mos
(!*********************************************************
   Mosel Python Example Problems
   =============================

   file invert_matrix.mos
   ``````````````````````
   Invert a Mosel matrix in Python using pandas and NumPy.

   !!! This example requires an installation of Python 3, see
   !!! chapter 'python3' of the 'Mosel Language Reference' for
   !!! compatible versions and setup instructions.

  (c) 2018 Fair Isaac Corporation
      author: J. Müller
*********************************************************!)
model "invert_matrix"
  options noimplicit

  uses "python3"
  uses "mmjobs"

  ! Input data
  declarations
    I, J: range
    A, A_inverse: array(I, J) of real
  end-declarations

  procedure show_matrix(B: array(I: range, J: range) of real)
    forall (i in I) do
      forall (j in J) do
        write(B(i, j), " ")
      end-do
      writeln
    end-do
  end-procedure

  writeln("Run Python script that defines invert_matrix function.")
  writeln("Python DSO version:     ", getdsoprop("python3", PROP_VERSION))
  pyinitpandas
  pyrun("invert_matrix.py")

  I := 0..2
  J := 0..2
  A :: [1,0,3,
        0,1,2,
        0,0,1]

  writeln("Mosel matrix A:")
  show_matrix(A)

  ! Optional: Delete old values from result matrix before calling function.
  delcell(A_inverse)

  writeln("Invert matrix with NumPy.")
  pycall("invert_matrix", A_inverse, A)

  writeln("Matrix A_inverse:")
  show_matrix(A_inverse)
end-model