Re: fix for eigenvectors function in eigen.mac

Hi Robert and Richard,

Actually it was due to a tellsimpafter rule in my quantum mechanics
package to replace cos(x) +/- %i*sin(x) --> e^(+/- %i*x). I mentioned
this in the maxima-bugs post. Once I removed the tellsimpafter rule
algsys no longer fails to find a solution. The bug should be marked
not-a-bug. https://sourceforge.net/p/maxima/bugs/4771

Sorry for the noise.

-Eric

On Wed, 2026-06-17 at 09:03 -0700, Richard Fateman wrote:
> according to documentation, solve() should look at the arguments and
> then
> as appropriate, call algsys() or linsolve().   Does solve() do the
> job?
> Also, it appears (from other info not posted to everyone) that the
> difficulty
> originates from giving algsys a non-algebraic problem, and that leads
> to
> failure by not
> noticing that sin^2 + cos^2 -1 is zero.
>   I wonder if, when solve() is given some kinds of problems, like a
> system
> of equations
> which contain trig functions, it would be helpful / not harmless  to
> run
> trigsimp() on the
> input.   (Running trigsimp() on a single equation would, I think, be
> potentially troublesome.)
> Could be controlled by yet another global flag, I suppose.
> solve_use_trigsimp ??
> 
> Bunches of test cases for solve() are probably needed to examine such
> options.
> RJF
> 
> 
> 
> On Tue, Jun 16, 2026 at 10:32 PM Robert Dodier
> <[email protected]>
> wrote:
> 
> > On Wed, Jun 10, 2026 at 2:12 PM ehm <[email protected]> wrote:
> > 
> > > Change the two lines
> > > 
> > > solution:algsys(equations,unknowns),
> > > interm:map('rhs,solution[1]),
> > > 
> > > to
> > > 
> > > solution:linsolve(equations,unknowns),
> > > interm:map('rhs,solution),
> > <snip>
> > 


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