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ForSolver
ForSolver: A Fortran library of linear and nonlinear solvers.
Usage
Linear system solver
use forsolver, only: solve
x = solve(A,b,method)
available methods (optional):
gesvgels
Nonlinear system solver
use forsolver, only: nlsolver
call nls%set_options(&
lin_method,&
nl_method,&
fdm_method,&
fdm_tol,&
cs_tol,&
TolFun,&
maxit,&
nmp,&
verbosity )
call nls%solve(F, dFdx, x0, x_sol)
available nl_methods:
newtonnewton-modifiednewton-quasi-fdnewton-quasi-fd-modifiednewton-quasi-csnewton-quasi-cs-modified
fd: finite difference method
cs: complex step method
Requirements
- A Fortran Compiler
- LAPACK, BLAS or MKL
- Fortran Package Manager (fpm)
fpm Dependency
If you want to use ForSolver as a dependency in your own fpm project,
you can easily include it by adding the following line to your fpm.toml file:
[dependencies]
forsolver = {git="https://github.com/gha3mi/forsolver.git"}
Runing Tests
Execute the following commands to run tests with specific compilers:
fpm @<compiler>-test
compiler: ifx, ifort, gfortran, nvfortran
Examples
Example 1: Linear System Solver
program example1
use kinds
use forsolver
implicit none
real(rk), dimension(:,:), allocatable :: A
real(rk), dimension(:) , allocatable :: x, b
integer :: m,n, i, j
m = 3
n = 2
allocate(A(m,n),b(m),x(n))
A(1,:) = [ 1.0_rk, 5.0_rk]
A(2,:) = [ 3.0_rk, 1.0_rk]
A(3,:) = [-2.0_rk, 4.0_rk]
b = [4.0_rk, -2.0_rk, 3.0_rk]
x = solve(A, b)
end program example1
Example 2: Newton's Method for Root Finding
module my_function3
use kinds
implicit none
contains
function F1(x) result(F_val)
real(rk), intent(in) :: x
real(rk) :: F_val
F_val = 5.0_rk * x**3 + 8.0_rk * x - 5.0_rk
end function F1
function dF1dx(x) result(dFdx_val)
real(rk), intent(in) :: x
real(rk) :: dFdx_val
dFdx_val = 15.0_rk * x**2 + 8.0_rk
end function dF1dx
end module my_function3
program example2
use forsolver
use my_function3
implicit none
type(nlsolver) :: nls
real(rk) :: x, expected_x
call nls%set_options(&
nl_method = 'newton',&
maxit = 100,&
TolFun = 1e-4_rk,&
verbosity = 1)
call nls%solve(F=F1, dFdx=dF1dx, x0=10.0_rk, x_sol=x)
end program example2
API Documentation
The most up-to-date API documentation for the master branch is available
here.
To generate the API documentation for ForSolver using
ford run the following
command:
ford ford.yml
Contributing
Contributions to ForSolver are welcome!
If you find any issues or would like to suggest improvements, please open an issue.