Just a very basic question from a beginner...

[guillaume_c]

Dear all,

I'm a wildlife scientist working in Sweden, and I would like to ask some naive questions.

I develop population models for wildlife managent purpose. The current models I have written (in R or Objective C) are too slow for complex simulations, so I have decided to give Fortran and Intel Fortran Compiler a try, as everyone tells they can make very fast programs. The powerfull array and vector manipulation features seem also very attractive. However, I'm encountering difficulties in using the MKL, and this probably because I'm not really familiar with command line compilation on UNIX. I suppose most of list members here are UNIX fluent, so my questions will likely take just a few seconds of your time. Thanks for your help!

I have for example this very simple program:

!#######################################################################
program model

integer :: i
real, allocatable :: pop(:)
real :: s

allocate(pop(1:100))
pop = 1
s = 0.99

do i=1,100
pop = pop*s
end do

print *, pop

end program model
!#######################################################################

What I'm unable to do is to have something like:

do i=1,100
pop = bernoulli(pop,s)
end do

For this I need to link with the MKL and use the function virngbernoulli( method, stream, n, r, p ) contained in include/mkl_vml.fi

I have tried to link by typing this:

ifort -std03 model.f90 -I/opt/intel/Compiler/11.0/056/Frameworks/mkl/include/mkl_vsl.fi

but this does not work. Neither does

ifort -std03 model.f90 -I/opt/intel/Compiler/11.0/056/Frameworks/mkl/include/

when I put include 'mkl_vsl.fi' in the program

I'm using Mac OS 10.5.5, with the latest evaluation version of the Intel Fortran Compiler. I need to use the -std03 option, as once I have this working, I would like to keep only the "1" in the array, and I suppose I can do it like this:

WHERE (pop == 1)
pop = pop
END WHERE

Well, probably simple for you. Thanks for any help I could get!

Cheers

Guillaume

[TimP]

You've already made this question too complicated for a beginner. For example, where you wrote

do i=1,100
pop = pop*s
end do

This has the same meaning as

do i=1,100

do j=1,100
pop(j) = pop(j)*s

end do
end do

The compiler may or may not do exactly what you intended, and I don't know what you intended. Even if I make the assumption that you didn't write this by mistake, it becomes impossible to give you a simple answer.

WHERE (pop == 1)

Is a way to select those array indices corresponding to elements of pop which have the exact value 1. This raises several issues which may not bear on the question you intended to ask.

MKL is primarily oriented toward Fortran 77 (no array syntax), although the BLAS95 interface provides some relief. There is a separate forum section on MKL.

[guillaume_c]

Thanks for your reply. In fact, my code was written to do exactly what you described. This looks very similar to R syntax, so it would require very few efforts to port a R simulation program to Fortran 2003 (which would run much faster). The Fortran 2003 feature of allocatable arrays in assigment statements is very useful for this. Thanks for the explanation about the MKL and its lack of vector support.

[Daniel_Gandolfo]

Quoting - tim18

You've already made this question too complicated for a beginner. For example, where you wrote

do i=1,100
pop = pop*s
end do

This has the same meaning as

do i=1,100

do j=1,100
pop(j) = pop(j)*s

end do
end do

The compiler may or may not do exactly what you intended, and I don't know what you intended. Even if I make the assumption that you didn't write this by mistake, it becomes impossible to give you a simple answer.

WHERE (pop == 1)

Is a way to select those array indices corresponding to elements of pop which have the exact value 1. This raises several issues which may not bear on the question you intended to ask.

MKL is primarily oriented toward Fortran 77 (no array syntax), although the BLAS95 interface provides some relief. There is a separate forum section on MKL.

Sorry but what about VSL ? It's included in MKL library and it does provide access to vector routines...