Here is a Fortran program which solves a system of linear equations: LIN_EQ.F It is compiled via: gfortran -o LIN_EQ LIN_EQ.F -llapack The program uses the LAPACK subroutine: DGESV * * * A version written in C/C++ is given at: linear_eq.cpp It is compiled via: gcc… Read more
MinGW should be installed first. Next… GotoBLAS2 GotoBLAS2 is an implementation of Basic Linear Algebra Subprograms (BLAS). LAPACK uses BLAS. GotoBLAS2 has configurations for a variety of hardware platforms. It builds a library that is optimized for the given PC’s CPU. Make a folder called:… Read more
Here is a Fortran program which performs matrix inversion using the LU decomposition method: INVERSE_MATRIX.F It is compiled via: gfortran -o INVERSE_MATRIX INVERSE_MATRIX.F -llapack It compiles & runs under both Ubuntu & Cygwin. See also: http://www.nag.com/numeric/fl/nagdoc_fl23/examples/source/f07ajfe.f90 * * * The INVERSE_MATRIX.F program uses the subroutines:… Read more
Here is a program that uses dgemm to multiply two matrices: matrix_mult.cpp The dgemm function is implemented using gsl blas. It can be compiled under Cygwin as: gcc -o matrix_mult_alt matrix_mult_alt.cpp -lgsl -lstdc++ And under Ubuntu as: gcc -o matrix_mult_alt matrix_mult_alt.cpp -lgsl -lgslcblas -lstdc++ *… Read more
Blas and Lapack may be installed on an Ubuntu system using the instructions at: Generalized Eigenvalue Problem * * * C++ programs that use Lapack can be compiled in Terminal or Bash shell mode via: g++ file_in -o file_out -lgfortran -llapack -lm where file_in is… Read more
The goal of this project is to solve a “very large” generalized eigenvalue problem in a “reasonable” amount of time using library functions. The mass and stiffness matrices may be either dense or sparse. Optimum routines are desired for each case. Here is description of… Read more