Re: Why is different ^ and .^?

[Mike Miller]

On Mon, 23 May 2005, Javier Arantegui wrote:

> octave:7> a=0:1:10;
> octave:8> a.^2
> ans =
>
>    0    1    4    9   16   25   36   49   64   81  100
>
> octave:9> a^2
> error: for A^b, A must be square
> error: evaluating binary operator `^' near line 9, column 2
>
> Why the second option (^ instead of .^) doesn't work? Shouldn't be 
> easier if you could use the same operator as when you are working with 
> an scalar? I'd be happy if you could provide me an explanation that I 
> could give to my students.


a^2 means a*a
a.^2 means "square every element of a"

a^2  therefore requires that 'a' be a square matrix or scalar.
a.^2 does not require that 'a' have any particular dimensions

Mike



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