out of memory problem! what to do for large matrix operations?

hi guys,

I am trying to solve some big numerical problems with VBA excel code
but when the dimension of matrix reaches to a critical number, for
example 7000x7000, compiler gives
"out of memory" problem. what to do in this situation?

thanks.

What are you trying to do? Is this really a MATLAB problem? See:

http://www.mathworks.com/products/ma...ctionlist.html

SteveM


MCM wrote:
> hi guys,
>
> I am trying to solve some big numerical problems with VBA excel code
> but when the dimension of matrix reaches to a critical number, for
> example 7000x7000, compiler gives
> "out of memory" problem. what to do in this situation?
>
> thanks.

SteveM wrote:
> What are you trying to do? Is this really a MATLAB problem? See:
>
> http://www.mathworks.com/products/ma...ctionlist.html
>
> SteveM
>
>


it is a numerical analysis code include some iterations. At every turn
for general loop it has to solve a linear equation set. I know that
some other software can be used but it is important to ose VBA excel
for this work. i.e. implementation of this kind of problem in VBA excel
is a part of the work. because some commercial reasons.

anyway thank you for suggestion.

If it's for a commercial app, the MATLAB cost is incidental ($2,000)
compared to coding a from scratch level of effort.

An inexpensive alternative is embedding a C coded module into your app.
See Numerical Recipes in C (60 bucks.) It shows you how to code all
of the matrix math.

http://www.amazon.com/gp/product/052...lance&n=283155

Also talk to the algorithm guys at the OR newsgroup. They may be able
to supply you with references to some open source code for matrix math:

http://groups.google.com/group/sci.op-research

SteveM.

MCM wrote:
> SteveM wrote:
> > What are you trying to do? Is this really a MATLAB problem? See:
> >
> > http://www.mathworks.com/products/ma...ctionlist.html
> >
> > SteveM
> >
> >
>
>
> it is a numerical analysis code include some iterations. At every turn
> for general loop it has to solve a linear equation set. I know that
> some other software can be used but it is important to ose VBA excel
> for this work. i.e. implementation of this kind of problem in VBA excel
> is a part of the work. because some commercial reasons.
>
> anyway thank you for suggestion.

Hi. Just an observation. My computer has 2 gigs of memory, and I get the
same "out of memory" error with this:

Dim m(1 To 7000, 1 To 7000) As Variant

When I switched it to Double, I was able to fill the array with numbers.

Dim m(1 To 7000, 1 To 7000) As Double

Don't know it that could help. Are you working with a Sparse array, where
most of the numbers are zero?
--
HTH. :>)
Dana DeLouis
Windows XP, Office 2003


"MCM" <[email protected]> wrote in message
news:[email protected]...
> hi guys,
>
> I am trying to solve some big numerical problems with VBA excel code
> but when the dimension of matrix reaches to a critical number, for
> example 7000x7000, compiler gives
> "out of memory" problem. what to do in this situation?
>
> thanks.
>