Re: simple advice needed on input and output

[Przemek Klosowski]

You requested the following things:

> Do I have to append ine by line to a file? Is that a bit slow? I
> have a lot of lines. about 10 000 000.

> I have a "for" loop in wich "i" ranges from 1 to say 5000. How can I
> make as many variables with the help of "i" to keep them in Octave
> memory?

> A * U * r * U * r
> A * U * r * U * s
> A * U * r * U * l

which makes me think that you want to perform 10 million matrix 
multiplies and store them  in a file in some organized way. You could do 
it by creating a column vector:

 for i=1:5000; r(i,1)=????; end
 save -ascii OutputFile r

The fundamental question is what is the pattern for those calculations. 
Surely you aren't planning to generate millions of matrix expressions 
like the three above by hand, so what is the plan here?

Maybe instead of generating the file with matrix expressions and then 
reading it back and executing, you could think of a way to specify those 
calculations directly in a loop, replacing the question marks I put in 
there?