Re: Very slow reading of a 2D matirx

[Bill Denney]

You didn't really choose the best method to load a matrix.  A better 
method would be to clip off the first two and the last lines from your 
attached .m file and change the name to something like xx.txt then do

load xx.txt

The 180x180 variable will be loaded into the variable xx.

Also, you invoked zero as:

x=zeros(1:180,1:180);

With that invocation, you're creating a 360 dimensional matrix with the 
dimensions 1x2x3x...x180x1x2x3x...x180.  You meant to call it as

x = zeros(180);

or more explicitly as

x = zeros(180,180);

That is probably where most of your time is taken.

Bill

On Wed, 19 Oct 2005, Alireza wrote:

> Hi,
>
> I have a moderately sized 2D array (180X180), that want to read into octave.
> The reading is extremely slow. I have tried to create the array first, but
> the speed is still the same.
>
> I have tried this on various machines and octave versions, from the rusty to
> bleeding!
>
> Any thoughts and suggestions as to why this is and what needs to be done!
>
> Thanks
> Ali

--
"During times of universal deceit, telling the truth becomes a
revolutionary act."
  -- George Orwell



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