A Fortran library for miscellaneous utilities such as data structures (List, Vector), root-finding for polynomials and nonlinear equations, etc.

Author: Bharat Mahajan (https://www.researchgate.net/profile/Bharat_Mahajan2)

Version: 0.1

Date: Created: 02/12/2020

Copyright: Copyright 2020 Bharat Mahajan

Repository

https://github.com/princemahajan/FMUTIL

Introduction

FMUTil is a modern object-oriented Fortran library that provides (as of now):

Data structures
- Vector (similar to C++ STL Vectors) with fast vector slicing
- List (similar to Python List)
Root-finding algorithms
- Polynomial roots by computing eigenvalues of the companion matirx (require Intel MKL)
- Roots of a nonlinear equation using Brent's algorithm
A simple binary search method for sorted arrays

How to Use

For Vector data structure of any type, define the type of the Vector element and the assignment operation as follows.

module testmodule
use fmutil
type, extends(vecelem) :: relem
    real :: rdata
contains
    procedure :: AssignVecElem => assign_relem
end type relem
 
contains
 
subroutine assign_relem(lhs, rhs)
    implicit none
    class(relem), intent(out) :: lhs
    class(VecElem), intent(in) :: rhs
    select type (rhs)
    class is (relem)
        lhs%rdata = rhs%rdata
    end select    
end subroutine assign_relem
end module TestModule

Then, use Vector using

program test
use fmutil
use testmodule
 
integer :: ctr
type(Vector) :: vec
type(relem) :: rd1, rd2
 
rd1%rdata = 3.1416
ctr = vec%PushBack(rd1)    
rd1%rdata = 2.718
call vec%Insert(2,[rd1, rd1])
 
do ctr = 1, vec%Size()
    rd2 = vec%ElemAt(ctr)
    print *, 'int(', ctr, ')=', rd2%rdata        
end do    
end program Test

List can be used as

program test
use fmutil
 
integer :: ctr
type(List) :: list
class(*), allocatable :: item
type(relem) :: rd1
rd1%rdata = 3.1416
 
ctr = list%PushBack(100)
ctr = list%PushBack(rd1)
ctr = list%PushBack(rd1%rdata)
ctr = list%Insert(3,'pi')    
 
do ctr = 1, list%Size()
    item = list%Item(ctr)
    select type (item)
    type is (real)
        print *, item
    type is (relem)
        print *, item
    type is (integer)
        print *, item
    type is (chanracter(len=*))
        print *, item
    end select
end do  
end program Test  

See the test program files, test.f90 and testmod.f90, in tests folder for more features and functionality.

Installation

FMUTIL is tested with Intel Fortran Compiler and MinGW-W64 gfortran. Doxyfile is provided for generating extensive API documentation using Doxygen. FMUTIL has only dependency on Intel MKL for polynomial root-finding. The CMakeLists file is provided along with additional CMake modules for compiler options and a Find module for finding and linking Intel MKL is also provided. These files can be used to auto generate Visual Studio projects or makefiles on Windows and Linux using CMake. A find module for FMUTIL is provided that generates CMake config files for easily linking FMUTIL using the find_package() command. The steps to link FMUTIL in cmake-based projects are:

Set the environment variable "MKLROOT" with the path to the Intel MKL installation directory. On typical Windows system, it looks something like "C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2019.0.117\windows\mkl"
Set the environment variable "IFORT_COMPILER20" with the path to the Fortran Compiler installation directory. On typical Windows system, it looks something like "C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2020\windows\"
In cmake GUI or command-line, set FMUTIL_INSTALL_LIB_DIR to the desired directory, where the compiled library, modules, and cmake config files will be installed.
In cmake GUI or command-line, set FMUTIL_INSTALL_BIN_DIR to the desired directory, where the compiled test executables will be installed.
In your project CMakeLists.txt, insert

find_package(fmutil required 0.1 config 
    paths "<SAME_PATH_AS_IN_FMUTIL_INSTALL_LIB_DIR>" no_cmake_package_registry)
target_link_libraries(<your_target_name> fmutil::fmutil)