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- Thread starter bastadoni
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too little information...
how huge is the matrix? have you calculated the amount of bytes is using and compared this against the amount of RAM you have in your computer?
are you using Fortran90 intrinsic function transpose()?
is this huge matrix static or dynamically allocated?
what operating system are you on?
how huge is the matrix? have you calculated the amount of bytes is using and compared this against the amount of RAM you have in your computer?
are you using Fortran90 intrinsic function transpose()?
is this huge matrix static or dynamically allocated?
what operating system are you on?
- Thread starter
- #3
Hello everyone and especially hello to Mr Salgerman who's always here for help ... Again thanks a lot.
My laptop is HP 350, 6G of RAM, i5 4th generation.
I work with Windows 64 bits, and i use Fortran 90 and I execute my programs with the 'invite commands' , I mean MsDos.
The matrix is really huge, the dimension of the matrix are about A(400000,150000),my study is to calculate the inverse, I mean calculate this quantity ( A^t .A )^-1 .For that I calculate A^transpose then, multiplication of A^t.A then finally I define a new matrix B=(A^t.A) which I want to calculate it's own inverse. I don't know why it took me so long, may be because I'm not a good programmer or may be because it's hard to do it.
Have a nice day to you'll .
My laptop is HP 350, 6G of RAM, i5 4th generation.
I work with Windows 64 bits, and i use Fortran 90 and I execute my programs with the 'invite commands' , I mean MsDos.
The matrix is really huge, the dimension of the matrix are about A(400000,150000),my study is to calculate the inverse, I mean calculate this quantity ( A^t .A )^-1 .For that I calculate A^transpose then, multiplication of A^t.A then finally I define a new matrix B=(A^t.A) which I want to calculate it's own inverse. I don't know why it took me so long, may be because I'm not a good programmer or may be because it's hard to do it.
Have a nice day to you'll .
Well, yes, that seems a bit large of a matrix for a program and even worse if you plan to have 2 or 3 of these matrices around.
As you can see, 400,000 x 150, 000 = 60, 000, 000, 000 entries; even if you are using single precision reals which are 4 bytes long, a matrix this size would require 240G of memory...clearly, you DO NOT have the RAM for this...heck, I hardly have the hard disk space for this in my laptop.
You may need to look into sparse matrix techniques.
As you can see, 400,000 x 150, 000 = 60, 000, 000, 000 entries; even if you are using single precision reals which are 4 bytes long, a matrix this size would require 240G of memory...clearly, you DO NOT have the RAM for this...heck, I hardly have the hard disk space for this in my laptop.
You may need to look into sparse matrix techniques.
- Thread starter
- #5
yeah i know the subroutine "SPARSE" and others like "DFPMIN" or "FRPRMN", for that I shall ask my promoteur that it would be better to do this mesures with those subroutines. Thank you Mr Salgerman for your time, i'm always here for you if you ever need anything.
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