>> From: Luis Goddyn "goddyn"
LinearSolve appears to be broken in both Maple 7 and Maple 8,
and across several platforms.
The problem appears occationally when the matrix has a real entry
and the solution is not unique.
Is this problem known? Does anyone have a fix or a workaround?
(I must solve a 20 by 40 system, and I am neither amused nor impressed!)
Luis Goddyn
Mathematics, Simon Fraser University
Currently on Study Leave at: Dept. of Mathematics, Louisiana State University
-------
> # Two small examples of the LinearSolve bug
> with(LinearAlgebra):
> <<1,1,0>|<1,1,0>|<0,0,1>>,<1,1,0>; LinearSolve(%); # Works correctly
[1 1 0] [1]
[ ] [ ]
[1 1 0], [1]
[ ] [ ]
[0 0 1] [0]
[1 - _t0[2]]
[ ]
[ _t0[2] ]
[ ]
[ 0 ]
> <<1,1,0>|<1,1,0>|<0,0,1.>>,<1,1,0>: LinearSolve(%); # Make one entry real
Error, (in LinearAlgebra:-LA_Main:-BackwardSubstitute)
Matrix must be in row-echelon form, zero rows at the bottom
> <<1.,1.,0.>|<0.,0.,0.>|<0.,0.,1.>>,<1.,1.,0.>: LinearSolve(%); # Example 2
Error, (in LinearAlgebra:-LA_Main:-BackwardSubstitute)
Matrix must be in row-echelon form, zero rows at the bottom
> interface(version);
TTY Iris, Maple 8.00, SGI MIPS UNIX, Apr 22 2002 Build ID 110847
|
(NAG)
