How to find out runtime version of Maxima? (confused by new format of eigenvectors() in 5.19.2)

Thanks Robert,

I'm sanguine about the exact mechanism, but would ask that
(1) it is a core Maima function and is documented,
(2) is stable over future versions (probably = simple!),
(3) can be used by Maxima mortals inside code to keep it working over 
different versions.

I like the idea of having a general build_info structure, since it makes 
sense to have all such information in one place.

Thanks!
Chris

On Wed, 16 Sep 2009, Robert Dodier wrote:

> On 9/16/09, Chris Sangwin <sangwinc at for.mat.bham.ac.uk> wrote:
>
>> MAXIMA_VERSION:map(parse_string, tokens(?\*autoconf\-version\*,
>> 'digitcharp));
>> MAXIMA_VERSION_NUM:float(MAXIMA_VERSION[2]+MAXIMA_VERSION[3]/10),
>
> Well, orderlessp compares lists directly -- no need to smash
> it into a number. Also, it's not guaranteed that versions are
> composed solely of numbers -- could be letters too.
>
>> ... in any case I'd love to have some way of knowing the runtime version
>> of Maxima which is stable over future versions inside the Maxima core!
>
> Well, here's an idea I had a while ago. Maybe it's time for this.
> What does anyone think of this? Idea is for build_info to return
> an expression instead of just print stuff to the console.
> The return value is a structure. You can extract bits of it via "@".
> (Sorry, undocumented features here ....)
>
> With the following patch applied, I get this:
>
> (%i2) foo : build_info () $
> (%i3) foo;
> (%o3)
> Maxima version: 5.19post
> Maxima build date: 2009-09-12 19:43:57
> Host type: i686-pc-linux-gnu
> Lisp implementation type: CLISP
> Lisp implementation version: 2.46 (2008-07-02) (built 3427839018)
> (memory 3461795063)
> (%i4) foo at version;
> (%o4)                       5.19post
> (%i5) foo at timestamp;
> (%o5)                  2009-09-12 19:43:57
> (%i6) grind (foo);
> ?%build_info("5.19post","2009-09-12 19:43:57",
>             "i686-pc-linux-gnu","CLISP",
>             "2.46 (2008-07-02) (built 3427839018) (memory 3461795063)")$
>
>
> What does anything think of that? Yes / no / maybe ??
>
> HTH
>
> Robert Dodier
>
> PS.
> Index: src/macsys.lisp