class FiniteDimensionalModulesWithBasis(CategoryWithAxiom_over_base_ring):
...
class MorphismMethods:
...
def matrix(self, base_ring=None, side="left"):
r"""
...
INPUT:
...
- ``side`` -- "left" or "right" (default: "left")
If ``side`` is "left", this morphism is considered as
acting on the left; i.e. each column of the matrix
represents the image of an element of the basis of the
domain.
.... but ....
class MatrixMorphism(MatrixMorphism_abstract):
...
def __init__(self, parent, A, copy_matrix=True, side='left'):
...
def matrix(self, side=None):
r"""
Return a matrix that defines this morphism.
INPUT:
- ``side`` -- (default: ``'None'``) the side of the matrix
where a vector is placed to effect the morphism (function)
OUTPUT:
...
Internally, Sage represents a matrix morphism with the
matrix multiplying a row vector placed to the left of the
matrix. If the option ``side='right'`` is used, then a
matrix is returned that acts on a vector to the right of
the matrix.
We have
.... but ....