# ThirdParty-Mumps

**Repository Path**: allingo/ThirdParty-Mumps

## Basic Information

- **Project Name**: ThirdParty-Mumps
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: EPL-2.0
- **Default Branch**: stable/3.0
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2024-12-30
- **Last Updated**: 2024-12-30

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# ThirdParty-Mumps

This is an autotools-based build system to build and install
[MUltifrontal Massively Parallel sparse direct Solver](http://mumps-solver.org/) (MUMPS).
This installation of MUMPS is used by some other COIN-OR projects.

This version of ThirdParty-Mumps retrieves and builds MUMPS 5.7.3.

## Dependencies

- MUMPS source requires a Fortran 90 compiler.

- MUMPS requires LAPACK to be available. `configure` will look for a Lapack
  installation, but if that does not succeed, the flags to link with Lapack
  should be specified with the `--with-lapack-lflags` argument of `configure`.

- MUMPS can make use of METIS. `configure` will look for a METIS library and
  header, but if that does not succeed, the arguments `--with-metis-lflags`
  and `--with-metis-cflags` can be specified for `configure`.

  Both Metis 4 and Metis 5 can be used with ThirdParty-Mumps.

## Installation steps

1. Obtain the MUMPS source code.

   **********************************************************************
   Note: It is YOUR RESPONSIBILITY to ensure that you are entitled to
         download and use this third party package.
   **********************************************************************

   The shell script `get.Mumps` can be used to automatically download and
   extract the correct version of the MUMPS source code. The script will
   first try to download from from https://coin-or-tools.github.io/ThirdParty-Mumps.
   If this fails, it will attempt to download from the MUMPS website: http://mumps-solver.org

   The script requires wget, curl, or fetch to be available on the system
   and in the shells search path (`$PATH`).

2. Run `./configure`. Use `./configure --help` to see available options.

3. Run `make` to build the MUMPS library.

4. Run `make install` to install the MUMPS library and header files.

## NOTE for GFortran users

MUMPS source does not compile out of the box when using GFortran 10 or higher, probably
due to some incompatibilities between assumed Fortran language standards,
see also [issue #4](https://github.com/coin-or-tools/ThirdParty-Mumps/issues/4).

As a workaround, `configure` adds `-std=legacy` to the Fortran compiler flags
if `$FC` matches `*gfortran*`.

## Single-precision codes

This buildsystem can also build a single-precision version of MUMPS.
To do so, use the configure option `--with-precision=single`.

It is also possible to build both single- and double-precision variants
of MUMPS into the same library by using `--with-precision=all`.

## 64-bit integers

This buildsystem can be instructed to change the integer type of MUMPS to
have a size of 64-bit by using the configure option `--with-intsize=64`.
This defines `MUMPS_INTSIZE64` instead of `MUMPS_INTSIZE32` in
`mumps_int_def.h` and instructs the Fortran compiler to use 8-byte integers.
The latter requires that the Fortran compiler is either GNU Fortran or
Intel Fortran.

When MUMPS uses 64-bit integers, also Lapack and METIS need to use 64-bit
integers. For METIS, this means that `IDXTYPEWIDTH` needs to be set to 8
instead of 4.