[Octave-bug-tracker] [bug #58830] imprecise error message for "size(foo, end)"

[anonymous]

Follow-up Comment #6, bug #58830 (project octave):

Rik, I see what you mean. Reporting the subscript and the dimensional
reasoning is extremely useful behavior when accidentally going out of bounds:


octave:2> mat = rand(3,4)
mat =

   0.6382   0.6235   0.7015   0.8218
   0.1992   0.6884   0.5041   0.9771
   0.7918   0.3789   0.7485   0.4995

octave:3> mat(end)
ans = 0.4995
octave:4> mat(end+1)
error: mat(13): out of bound 12 (dimensions are 3x4)
octave:5> mat(0)
error: mat(0): subscripts must be either integers 1 to (2^63)-1 or logicals
octave:6> mat(-1)
error: mat(-1): subscripts must be either integers 1 to (2^63)-1 or logicals
octave:7> mat(end-13)
error: mat(-1): subscripts must be either integers 1 to (2^63)-1 or logicals
octave:8> mat(nan)
error: mat(nan): subscripts must be either integers 1 to (2^63)-1 or logicals


The occasional quirk is that incorrectly calling a function with end as an
argument causes behavior that is very consistent with "end == nan" but can
surprise a user who doesn't know that equivalence:

octave:9> size(end)
ans =
   1   1
octave:10> size(nan)
ans =
   1   1
octave:11> isnan(end)
ans =
   1


Though it can be surprising, it is likely easily noticed and fixed.

If it's relevant, could you check Matlab's error message for "isnan(end)"
please? Is it a blanket error message or does it give info relevant to the
calling location?

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