Hi, everyone! I’m new to Julia and I’m trying to implement some existing Fortran libraries to use in Julia code. However, the ccall function does not appear to change the values of variables which I pass to it. A simplified version of Fortran code is: SUBROUTINE TEST (IOPT,PARMOD,PS,X,Y,Z,VX,VY,…

For mutable scalar variables, you need to wrap in Ref: see “Calling C and Fortran code: Passing pointers for modifying inputs” in the manual (the description mentions C, but applies to Fortran too). Also note that the default kind for REAL in Fortran is usually Float32.

There are some simple examples here: [image] Calling fortran function New to Julia Also here is a simple example: subroutine foo1(n,x,y) integer*4, intent(in) :: n integer*4, intent(in), dimension(n) :: x integer*4, intent(out), dimension(n) :: y …

Thanks for your help. @Ralph_Smith pointed me in the right direction. Changing the definition of mutable variables to: Vx = Ref{Cdouble}(-1e31) Vy = Ref{Cdouble}(-1e31) Vz = Ref{Cdouble}(-1e31) resolved the problem.

Using compiled Fortran shared library

New to Julia

Mattriks September 29, 2018, 10:29pm 3

There are some simple examples here:

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Using compiled Fortran shared library

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