Hello, I wonder about the following behavior
In [1]: import sympy as sp In [2]: x, y = sp.symbols('x, y', commutative = False) In [3]: M1 = x*sp.eye(2) In [4]: M2 = y*x*sp.eye(2) In [5]: y*M1-M2 Out[5]: Matrix([ [x*y - y*x, 0], [ 0, x*y - y*x]]) I would have expected that the two matrices are equal. However, multiplying y from the right to M1 results in products where y is on the left side: In [6]: y*M1 Out[6]: Matrix([ [x*y, 0], [ 0, x*y]]) For reference two other results: In [7]: M2 Out[7]: Matrix([ [y*x, 0], [ 0, y*x]]) In [8]: M1*y Out[8]: Matrix([ [x*y, 0], [ 0, x*y]]) Questions: 1. Is this behavior intended? 2. Is there any (easy) way to achieve my intended behavior, i.e. respecting multiplication order when using matrix multiplication. Thanks, Carsten. -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/55510F66.4060900%40gmx.de. For more options, visit https://groups.google.com/d/optout.