nonpivots

compas.numerical.nonpivots(U, tol=None)[source]

Identify the non-pivots of input matrix U.

Parameters

U (array-like) – Matrix U represented as an array or list.

Returns

list – Non-pivot column indices.

Notes

If the matrix U is in Reduced Row Echelon Form, the nonpivots are the columns with non-zero coefficients that are not leading their row.

Examples

>>> A = [[1, 0, 1, 3], [2, 3, 4, 7], [-1, -3, -3, -4]]
>>> n = rref_sympy(A)
>>> nonpivots(n)
[2, 3]