.Modelica.Math.Matrices.solve

Information

Syntax

Matrices.solve(A,b);

Description

This function call returns the solution x of the linear system of equations

A*x = b

If a unique solution x does not exist (since A is singular), an assertion is triggered. If this is not desired, use instead Matrices.leastSquares and inquire the singularity of the solution with the return argument rank (a unique solution is computed if rank = size(A,1)).

Note, the solution is computed with the LAPACK function "dgesv", i.e., by Gaussian elimination with partial pivoting.

Example

  Real A[3,3] = [1,2,3;
                 3,4,5;
                 2,1,4];
  Real b[3] = {10,22,12};
  Real x[3];
algorithm
  x := Matrices.solve(A,b);  // x = {3,2,1}

Interface

function solve
  extends Modelica.Icons.Function;
  input Real A[:, size(A, 1)] "Matrix A of A*x = b";
  input Real b[size(A, 1)] "Vector b of A*x = b";
  output Real x[size(b, 1)] "Vector x such that A*x = b";
end solve;