On 5/21/20 8:44 PM, AlexGhitza wrote: > Hi, > > I'm observing the following with version 9.1 (but not with 9.0 where the > behavior is correct): > > sage: m = matrix(SR, [0]) > sage: b = vector([1]) > sage: m.solve_right(b) > (0) > > This should of course raise > > ValueError: matrix equation has no solutions > > > It seems to be specific to inexact coefficients (the same problem occurs > for RR and CC, but not for QQ). >
This was changed to "do what MATLAB does" because of the numerical issues inherent to inexact rings. While m = matrix(SR, [0]) is singular and the system `m*x == [1]` has no solutions, with m = matrix(SR, [0.0000000000000000000001]), the system is easily solvable and we can't tell the difference between the two. I think the real surprise here is that SR is an inexact ring. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/ba76c21c-8042-3a50-c881-704b62598367%40orlitzky.com.
