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

If you compare version strings as strings, then 10.1.0 < 9.1.0 and
1.10.1 < 1.9.1... not what one usually wants.

          -s

On 9/16/09, Leo Butler <l.butler at ed.ac.uk> wrote:
>
>
> On Wed, 16 Sep 2009, Alexander Shulgin wrote:
>
> < On Fri, Sep 4, 2009 at 13:20, Andrej Vodopivec
> < <andrej.vodopivec at gmail.com> wrote:
> < > Lisp variable *autoconf-version* contains the version as a string. You
> < > can then use stringproc functions to compare versions.
> < >
> < > (%i1) version: ?\*autoconf\-version\*;
> < > (%o1) 5.19.2
> <
> < Thanks, this worked! :)
> <
> < I've come up with the following:
> <
> < maxima_version() :=
> <   map(parse_string, tokens(?\*autoconf\-version\*, 'digitcharp));
> <
> < version_compare(v1, v2) := block(
> <   [len1: length(v1), len2: length(v2), v, i, cmp: 0],
> <   if len2 > len1 then v1: append(v1, makelist(0, i, 1, len2 - len1)),
> <   if len1 > len2 then v2: append(v2, makelist(0, i, 1, len1 - len2)),
> <   v: v1 - v2,
> <   i: 1,
> <   while i <= length(v) and cmp = 0 do
> <     (cmp: v[i],
> <      i: i + 1),
> <   cmp);
>
> I notice that stringproc has imported the lisp character comparison
> functions, but only the string= function. As a result, you have written
> lots of code to overcome this. Here is an alternative,
>
>
> slessp(s1,s2):=if stringp(s1) and stringp(s2) then ?string\<(s1,s2) else
> error("...");
>
> vc(v):= if stringp(v) then if slessp(?\*autoconf\-version\*,v)#false then 1
> elseif
> slessp(v,?\*autoconf\-version\*)#false then -1 else 0 else error("...");
>
> The first function imports lisp's string< to maxima, and the second does
> the comparison you want.
>
> (%i15) vc("5.18.1");
>
> (%o15) 0
> (%i16) vc("5.18.0");
>
> (%o16) -1
> (%i17) vc("5.19.1");
>
> (%o17) 1
>
>
>
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