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Re: N_ELEMENTS and WHERE: Scalar or Array ? [message #14261 is a reply to message #14130]

Thu, 04 February 1999 00:00

David Ritscher
Messages: 30
Registered: August 1995

Member

> 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

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[Message index]

		N_ELEMENTS and WHERE: Scalar or Array ? By: rmlongfield on Fri, 29 January 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: davidf on Wed, 03 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: steinhh on Wed, 03 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: wmc on Wed, 03 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: wmc on Wed, 03 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: Jack Saba on Tue, 02 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: steinhh on Tue, 02 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: Craig Markwardt on Mon, 01 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: wmc on Mon, 01 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: steinhh on Mon, 01 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: wmc on Mon, 01 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: Mark Buckley on Fri, 29 January 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: davidf on Fri, 29 January 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: David Ritscher on Fri, 29 January 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: David Kastrup on Fri, 29 January 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: R.Bauer on Fri, 29 January 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: David Ritscher on Thu, 04 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: Michael Werger on Thu, 04 February 1999 00:00
		Re: N_ELEMENTS and WHERE: Scalar or Array ? By: Annette Schloss on Wed, 03 February 1999 00:00

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