After MPI has been installed, use mpif.h and other source-code files provided with the MPI implementation that is installed on your computer(s) when MODFLOW-2000 is compiled with para-mpi.f. The mpif.h file and MPI subroutines referenced in the para-mpi.f file and other locations in the MODFLOW source code will be provided as part of the MPI installation. MPI software is not distributed by the USGS and must be obtained and installed separately. To enable the parallel-processing capabilities of MODFLOW-2000, an implementation of MPI must first be installed on your computer(s). If you wish to compile a parallel version of MODFLOW-2000, you will need to get a copy of mpif.h. If you have information on how to compile it with another compiler, please send to so it can be included on this web page.

However, no attempt has been made to test all Fortran compilers. This web page gives advice on compiling MODFLOW-2000 with some compilers. Users should try to find the switches in the compilers and linkers that control how names are decorated so that the object code generated by the C and Fortran compilers use consistent names. Often the C compiler will 'decorate' the name of the C function and the linker can't figure out how to link Fortran object code with an undecorated name with C object code with a decorated name.

If one is not aware that the C language is case-sensitive and the Fortran language is case insensitive, some error messages returned by compilers may be difficult to understand. Now, instead of just a Fortran compiler, a C compiler is also required. This makes compiling MODFLOW-2000 a bit more challenging than previously. However, the GMG package added in version 1.15.00 is written primarily in C (with a small amount of Fortran code to link to the C code). Prior to version 1.15.00, MODFLOW-2000 was written entirely in Fortran. There are extensive comments in openspec.inc that can help you. Be sure to modify this file to the correct form for your compiler. This compiler dependent code is included in the file 'openspec.inc'. However, a small portion of the code uses compiler-dependent code. Nearly all the Fortran code in MODFLOW is standard Fortran that will compile the same way with any compiler. However, if you wish to make changes to the source code, you will need to compile it yourself. Most users will not need to compile MODFLOW-2000 because you can download a compiled version of MODFLOW-2000 from the USGS web site.

Install fortran compiler on codeblock