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Topic: How to retrieve the given column of the data of arbitrary size?
Replies: 7   Last Post: Nov 18, 2012 6:14 PM

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Paul

Posts: 17
Registered: 5/18/11
Re: How to retrieve the given column of the data of arbitrary size?
Posted: Nov 18, 2012 6:14 PM
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"Steven_Lord" <slord@mathworks.com> wrote in message <k80civ$n39$1@newscl01ah.mathworks.com>...
>
>
> "Jan Simon" <matlab.THIS_YEAR@nMINUSsimon.de> wrote in message
> news:k7thlr$qm2$1@newscl01ah.mathworks.com...

> > Dear Bruno,
> >> ind = {':', 3, ':', ':' };
> >> A3=squeeze(A(ind{:}))

> >
> > I like this method. It is used in Matlab's toolbox functions, but is it
> > documented also?

>
> I don't believe it's explicitly documented. This is about as close as the
> documentation gets to describing that behavior.
>
> http://www.mathworks.com/help/matlab/matlab_oop/indexed-reference-and-assignment.html#br09e97-1
>
> " A colon used as an index is passed in the cell array as the string ':'. "
>
> --
> Steve Lord
> slord@mathworks.com
> To contact Technical Support use the Contact Us link on
> http://www.mathworks.com


One would think that this behavior (and any other aspects of indexing for Matlab arrays) should be documented here:
http://www.mathworks.com/help/matlab/math/matrix-indexing.html

Also, (at least in earlier versions of Matlab), indexing with characters is allowed, like this:
A('a') and A('ab'). Since that wasn't documented, it's not clear if that's supposed to be legal syntax. Further confusing the issue is that A('a') and A(':') are treated inconsistently. The former returns a single element of A (converting 'a' to its ASCII code I believe) and the latter returns all of A.



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