LAPACK95

Archive / mirror of Netlib LAPACK95, with added cmake support.

See also scivision/LAPACK95 with a different cmake implementation.

Build and install (cmake)

(Note: This compiles the full single_double_complex_dcomplex version.)

The standard procedure

mkdir build && cd build
cmake .. [-DCMAKE_INSTALL_PREFIX=/your/install/path (default: /usr/local)]
make -j$(nproc)

gives liblapack95.a, with module files placed in include/. Your program can then use f95_lapack and be compiled with e.g.

gfortran yourprogram.f90 -I/path/to/LAPACK95/build/include -L/path/to/LAPACK95/build -llapack -llapack95

(assuming ordinary LAPACK is in your path).

Install with (still in the build folder)

make install

(may require sudo depending on install location). Programs can then be compiled with

gfortran yourprogram.f90 -I/your/install/prefix/include -llapack -llapack95

(assuming /your/install/prefix/lib is part of LD_LIBRARY_PATH).

Use in a cmake project

This library can be used inside a cmake project by adding this repository with add_subdirectory. One can for example use FetchContent:

cmake_minimum_required(VERSION 3.11)

project(myproject Fortran)

find_package(LAPACK REQUIRED)

include(FetchContent)
FetchContent_Declare(
    lapack95
    GIT_REPOSITORY https://github.com/anjohan/LAPACK95.git
)

FetchContent_GetProperties(lapack95)
if(NOT lapack95_POPULATED)
    FetchContent_Populate(lapack95)
    add_subdirectory(${lapack95_SOURCE_DIR})
endif()

add_executable(myexe ${CMAKE_CURRENT_SOURCE_DIR}/myexe.f90)
target_link_libraries(myexe ${LAPACK_LIBRARIES} lapack95)

Example program

program ex
    ! Double precision
    use la_precision, only: wp => dp
    use f95_lapack, only: la_gesv

    real(wp) :: A(3,3), b(3)

    call random_number(A)
    b(:) = 3*A(:,1) + 2*A(:,2) - A(:,3)
    
    ! Solve Ax=b, overwrite b with solution
    call la_gesv(A,b)

    write(*,*) b
end program

! Output (exact: 3 2 -1):
! 2.9999999999999978        2.0000000000000018       -1.0000000000000004

Build (makefiles)

To build LAPACK95 library with any Fortran compiler simply:

cd LAPACK95/
make clean -C SRC

make double -C SRC

which creates lapack95.a in LAPACK95/ with "double" precision. Use "single" or other options described in tne README files under LAPACK95 and LAPACK95/SRC if complex etc. precision is needed.