[Octave-bug-tracker] [bug #54275] repelem error if a repeat instruction is a vector that ends with 0

[Rik]

Update of bug #54275 (project octave):

                  Status:                    None => Fixed                  
             Open/Closed:                    Open => Closed                 
                 Summary: repelem error if a repeat instruction is a vector
ends with 0 => repelem error if a repeat instruction is a vector that ends
with 0

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Follow-up Comment #2:

Confirmed.  As noted in the title, this is a problem only when the last
position is a 0.

I would prefer not to call out to a second function (repelems) because there
is a fair amount of interpreter overhead in calling a function.

Since methods 1 and 3 both work, the only question is performance.  I made a
small benchmark


N = 1e4;

bm = zeros (N, 1);

base = [1:10];
rep  = [9:-1:0];

for i = 1:N
  tic;
  c = repelem (base, rep);
  bm(i) = toc;
endfor


The results are



Patch 1:
------------------------------------------------------------
octave:11> mean (bm)
ans =  0.00017877
octave:12> median (bm)
ans =  0.00016284
octave:13> std (bm)
ans =  0.000072822


Patch 3:
------------------------------------------------------------
octave:5> mean (bm)
ans =  0.00015290
octave:4> median (bm)
ans =  0.00013614
octave:6> std (bm)
ans =  0.000080379


Patch three is the winner (although we're only talking about 20
milliseconds).

I committed the patch to the stable branch here
(http://hg.savannah.gnu.org/hgweb/octave/rev/9277b77dd28f).

Marking as fixed and closing report.


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