[Maxima-bugs] [maxima:bugs] #2596 error in matrix exponentiation

[Barton W. <wil...@us...>]

Fixed by Commit [c5762f] .  Closing ticket.


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**[bugs:#2596] error in matrix exponentiation**

**Status:** closed
**Group:** None
**Labels:** matrixexp 
**Created:** Wed Jun 19, 2013 01:40 PM UTC by kcrisman
**Last Updated:** Thu Sep 03, 2026 04:16 PM UTC
**Owner:** nobody


This is a regression in 5.30.0 from 5.29.1:
```
(%i1) m: matrix([%i*%pi]);
(%o1)                             [ %i %pi ]
(%i6) matrixexp(m),keepfloat:true;

Unable to find the spectral representation
 -- an error. To debug this try: debugmode(true);
(%i7) matrixexp(m),keepfloat:false;

Unable to find the spectral representation
 -- an error. To debug this try: debugmode(true);
```

Point of info - Barton W. has a workaround:

This bug is due to circa January 2013 changes to matrix inversion. A workaround is to set ratmx to true:
```
Maxima branch_5_30_base_98_g29f9239_dirty http://maxima.sourceforge.net
using Lisp Clozure Common Lisp Version 1.9-r15764  (WindowsX8632)

(%i1) matrixexp(matrix([%i*%pi]));

Unable to find the spectral representation

(%i2) matrixexp(matrix([%i*%pi])), ratmx=true;
(%o2)                                 - 1
```


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