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

orderlessp does the right thing with lists (lexicographic comparison),
but not the right thing with numbers represented as strings:

    orderlessp(["1","10"], ["1","9"]) => true

By the way, "is" does not use lexicographic order:

    is([1,2]<[2,3]) => unknown

This is probably appropriate, since in many of the uses of lists (e.g.
vectors), there is no well-defined order.

On the other hand, "is" fails with an internal error (which is never
appropriate) when applied to strings:

     is("1"<"2")
     Maxima encountered a Lisp error:
     Error in PROGN [or a callee]: Caught fatal error [memory may be damaged]

Or maybe this has been fixed since 5.17.1/GCL/Windows?

           -s

On Wed, Sep 16, 2009 at 12:54 PM, Robert Dodier <robert.dodier at gmail.com> wrote:
> On 9/16/09, Alexander Shulgin <alex.shulgin at gmail.com> wrote:
>
>> maxima_version() :=
>> ? map(parse_string, tokens(?\*autoconf\-version\*, 'digitcharp));
>
> Maybe this can be simplified somewhat.
>
> split (?\*autoconf\-version\*, ".");
> ?=> ["5","19","2"]
>
> Note that the result of split is a list of strings.
> Incidentally it's not guaranteed that each element is just
> a number --- there have been (and there continue to be)
> version numbers which are numbers & letters combined.
>
>> 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);
>>
>
> A custom comparison function isn't necessary.
> orderlessp does the right thing with lists.
>
> orderlessp (["5", "19", "1"], ["5", "19", "2"]);
> ?=> true
>
> HTH
>
> Robert Dodier
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>