I noticed some methods of BasicMatrix use a trick to create a zero matrix, then compiling its values and returning it, e.g.
newmat = self.zeros(self.rows, self.cols + rhs.cols) newmat[:, :self.cols] = self newmat[:, self.cols:] = rhs return newmat This works well for MutableMatrix, unfortunately self.zeros called on an instance of ImmutableMatrix returns and ImmutableMatrix of zeros which is immutable, raising an error on assignment. A workaround would be to replace self.zeros( ... ) with MutableMatrix.zeros( ... ) and then replace return newmat with return type(self)(newmat). Otherwise one could devise a way to allow __setitem__ to work on ImmutableMatrix as well, maybe returning a new matrix instead of modifying it. Or maybe a better idea would be to use some .replace_somewhat( ... ) method, acting the same way as __setitem__, but returning a new matrix instead of modifying the current matrix. What do you think? -- 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. For more options, visit https://groups.google.com/groups/opt_out.