From bug-octave-request at bevo dot che dot wisc dot edu Wed Dec 10 10:02:31 2003
Subject: Failure of mean.m on certain Nd arrays
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: Quentin Spencer <qspencer at ieee dot org>
Cc: bug-octave at bevo dot che dot wisc dot edu
Date: Wed, 10 Dec 2003 01:22:59 -0600

On 29-Nov-2003, Quentin Spencer <qspencer at ieee dot org> wrote:

| The following produces an error in version 2.1.52:
| 
| octave> size(x)
| ans =
| 
|         1        10        1000
| 
| octave> y=mean(x);
| error: invalid converstion of ComplexNDArray to ComplexMatrix
| error: evaluating postfix operator `.'' near line 91, column 10
| error: evaluating assignment expression near line 91, column 7
| error: evaluating if command near line 90, column 3
| error: called from `mean' in file 
| `/usr/share/octave/2.1.52/m/statistics/base/mean.m'
| 
| 
| proposed fix:
| -----------------
| The error comes from the code that I have removed in the following 
| patch. I may be missing something, but it appears to me that this was 
| the original solution to the problem of singleton dimensions before Nd 
| arrays were implemented, and I think this problem is now solved by the 
| subsequent "need-dim" code.
| 
| As a further suggestion, I think a more helpful error message for cases 
| when a transpose is attempted on a Nd array would be along the lines of 
| MATLAB's error message stating that such an operation is not defined for 
| N-dimensional arrays.
| 
| 
| 
| *** mean.m~     2003-11-29 19:36:49.000000000 -0600
| --- mean.m      2003-11-29 19:42:50.000000000 -0600
| ***************
| *** 87,96 ****
|       usage ("mean (x, dim, opt) or mean (x, dim, opt)");
|     endif
| 
| -   if (rows (x) == 1)
| -     x = x.';
| -   endif
| -
|     if (need_dim)
|       t = find (size (x) != 1);
|       if (isempty (t))
| --- 87,92 ----

I applied this patch and improved the error messages for attempted
N-d transposes.

Thanks,

jwe



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