Re: N_ELEMENTS and WHERE: Scalar or Array ?

[David Ritscher <david.ritscher(at)bigfoot.com>]

>wh_one = where(x GT 1)
>x[wh_ine] = 0              ; NOTE the type

>Because of the typo, the second statement would have the mysterious
>side effect of having no effect at all! (including no error message) I
>would still love to have it, but newbies might go crazy.

For questions regarding subscript handling, it's always worth looking
at how MATLAB does things.  They have a null array as a possible
variable, and seem to handle well what happens with this (logically
enough, when one indexes an array with a null array, the result is
null):


>> a = [1, 2]

a =

     1     2

>> b = []

b =

     []

>> a(b)

ans =

     []

>> 
>> whos
  Name      Size         Bytes  Class

  a         1x2             16  double array
  ans       0x0              0  double array
  b         0x0              0  double array

Grand total is 2 elements using 16 bytes



David Ritscher
-- 
Cardiac Rhythm Management Laboratory
Department of Medicine
University of Alabama at Birmingham
B168 Volker Hall  -  1670 University Boulevard
Birmingham  AL  35294-0019
Tel: (205) 975-2122      Fax:   (205) 975-4720
Email: david.ritscher@bigfoot.com