We should open an issue even if there isn't consensus. The current "don't evaluate by default" behavior was due to part of the conversation in this thread (Look for a post a fair ways down by Mateusz) https://groups.google.com/d/topic/sympy/ekqyrxezwQ0/discussion
I think there should still be a way to create unevaluated MatMul's of ImmutableMatrices but that it should not be default. We've had far more requests recently for default evaluation than otherwise. Also, you should be able to turn ImmutableMatrix(Matrix(instance_of_MatrixExpr)) into just ImmutableMatrix(instance_of_MatrixExpr). Glad to see that they're being used. On Thu, Mar 22, 2012 at 2:18 PM, [email protected] < [email protected]> wrote: > This was already mentioned. Expressions of ImmutableMatrices are not > evaluated by default. A few people mentioned that they prefer > automatic evaluation. I also lean toward that choice. If there is > consensus on this topic I would open an issue for it. > > > > Details: > The reason I want automatic evaluation is that I am working on some > hackish implementation of <some math object> and I have a ton of > ```ImmutableMatrix(Matrix(instance_of_MatrixExpr))``` snippets. I need > ImmutableMatrix because of the implementation of __hash__. In another > thread I have posed a related question. > > <some math object> in my case is quantum field theory tensors in Dirac > x Lorentz space > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > > -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
