To me, evaluation and immutability are completely separate. We should have separate subclasses to do each (UnevaluatedImmutableMatrix is probably better than ImmutableMatrix(evaluate=False)).
Aaron Meurer On Thu, Mar 22, 2012 at 3:34 PM, Matthew Rocklin <[email protected]> wrote: > 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. -- 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.
