Re: sum() behaving erratically?

[John W. Eaton]

On  7-Oct-2004, Francesco Potorti` <address@hidden> wrote:

| >> If I let a=[1,2;3,4]; and then ask for sum(a), sum(a,1) and sum(a,2), I
| >> get the answers
| >>
| >> 4 6     4 6     3
| >>                 7
| >>
| >> respectively. Now I let a=[1,2]; and do the same. I now get
| >>
| >> 3       1 2     3
| >>
| >> indicating that in the second case sum(a) != sum(a,1), in direct
| >> violation of the documentation in the manual. Is this supposed to be
| >> like this and didn't I understand things, or is it a bug? (Octave is
| >> 2.1.57.)
| 
| >This is a case of bug-for-bug compatibility.
| 
| In fact, it is a bug in the manual and the help.  Here is a patch:
| 
|   -- Built-in Function:  sum (X, DIM)
|       Sum of elements along dimension DIM.  If DIM is omitted, it
| !     defaults to 1 (column-wise sum).
| !     defaults to 1 (column-wise sum) unless the argument is a
| +     vector, in which case the sum of elements is returned.
| 
| Or, one could specify "unless the argument is a row vector".

I fixed the documentation for sum, prod, sumsq, cumsum, and cumprod.

Thanks,

jwe



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