sympy 中矩阵的按列（或按行）操作

Question

Is there a way to do column-wise (or row-wise) operations on matrices in sympy? For example, dividing each column of a matrix by its norm, or multiplying each row of a matrix by its norm?

Answer 1

You can use row_op and col_op . From the documentation for row_op :

row_op(i, f) method of sympy.matrices.dense.MutableDenseMatrix instance
    In-place operation on row ``i`` using two-arg functor whose args are
    interpreted as ``(self[i, j], j)``.

These methods act in-place:

>>> a = Matrix([[1, 2], [3, 4]])
>>> a.row_op(1, lambda i, j: i*2)
>>> a
Matrix([
[1, 2],
[6, 8]])