Usage example of SLATEC

BESFUN.FOR

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C                                                                      C
C     Compute the values for the Bessel function of the first kind     C
C     and order 0 in the interval [XA,XB] with N points.               C
C                                                                      C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C                                                                      C
C     AUTHOR: NICOLAS GUARIN Z.                                        C
C     GRUPO DE MECANICA APLICADA- UNIVERSIDAD EAFIT                    C
C     LAST MOD: 25 JULY 2012                                           C
C                                                                      C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C23456789012345678901234567890123456789012345678901234567890123456789012

      PROGRAM BESFUN
        IMPLICIT REAL*8(A-H,O-Z)
        ALLOCATABLE X(:), Y(:)

        OPEN(UNIT=7,FILE ="BESFUN.txt",STATUS="UNKNOWN")

        WRITE(*,*) "Number of points in x-axis: "
        READ(*,*) N
        WRITE(*,*) "Initial X - Final X: "
        READ(*,*) XA, XB
        ALLOCATE(X(N),Y(N))

        DO I=1,N
           X(I) = XA + (I-1)*(XB-XA)/(N-1)
           Y(I) = BESJ0(X(I))
           WRITE(7,*) X(I),Y(I)
      END DO
      END PROGRAM BESFUN

EIGSOL.FOR

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C                                                                      C
C     Compute the eigenvalues for a symmetric matrix stored in a       C
C     given file using SLATEC libray.                                  C
C                                                                      C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C                                                                      C
C     AUTHOR: NICOLAS GUARIN Z.                                        C
C     GRUPO DE MECANICA APLICADA- UNIVERSIDAD EAFIT                    C
C     LAST MOD: 25 JULY 2012                                           C
C                                                                      C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C23456789012345678901234567890123456789012345678901234567890123456789012

      PROGRAM EIGSOL
        IMPLICIT REAL(A-H,O-Z)
        ALLOCATABLE AMAT(:,:), EVALS(:), EVECS(:,:), FV1(:), FV2(:),
     1              EX_EVALS(:)

        OPEN(UNIT=7,FILE ="EIGSOL.mat",STATUS="UNKNOWN")
        OPEN(UNIT=8,FILE ="EIGSOL.evals",STATUS="UNKNOWN")

        READ(7,*) N
        ALLOCATE(AMAT(N,N),EVALS(N),EVECS(N,N),FV1(N),FV2(N),
     1           EX_EVALS(N))

        DO I=1,N
            READ(7,*) (AMAT(I,J),J=1,N)
            READ(8,*) EX_EVALS(I)
        END DO

        CALL RS(N,N,AMAT,EVALS,0,EVECS,FV1,FV2,IERR)
        
        WRITE(*,*) "Analytical Eigenvalues: ", EX_EVALS
        WRITE(*,*) "Computed Eigenvalues: ", EVALS

      END PROGRAM EIGSOL

LINSOL.FOR

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C                                                                      C
C     Compute the eigenvalues for a symmetric matrix stored in a       C
C     given file using SLATEC libray.                                  C
C                                                                      C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C                                                                      C
C     AUTHOR: NICOLAS GUARIN Z.                                        C
C     GRUPO DE MECANICA APLICADA- UNIVERSIDAD EAFIT                    C
C     LAST MOD: 25 JULY 2012                                           C
C                                                                      C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C23456789012345678901234567890123456789012345678901234567890123456789012

      PROGRAM LINSOL
        IMPLICIT REAL*8(A-H,O-Z)
        ALLOCATABLE AMAT(:,:), RHS(:), EX_SOL(:), WORK(:), IWORK(:)

        OPEN(UNIT=7,FILE ="LINSOL.mat",STATUS="UNKNOWN")
        OPEN(UNIT=8,FILE ="LINSOL.sol",STATUS="UNKNOWN")

        READ(7,*) N
        ALLOCATE(AMAT(N,N),RHS(N),EX_SOL(N),WORK(N),IWORK(N))

        DO I=1,N
            READ(7,*) (AMAT(I,J),J=1,N)
            READ(8,*) EX_SOL(I)
        END DO

        DO I=1,N
            READ(7,*) RHS(I)
        END DO

        IND = 7
        CALL DGEFS(AMAT,N,N,RHS,1,IND,WORK,IWORK)
        

        WRITE(*,*) "Analytical Solution: ", EX_SOL
        WRITE(*,*) "Computed Solution: ", RHS

      END PROGRAM LINSOL

test.sh

#!/bin/bash

# BESFUN.FOR
echo -e "\n=== Bessel Function Computation ===\n"
gfortran -o BESFUN.o BESFUN.FOR  -lslatec
./BESFUN.o

#LINSOL.FOR
echo -e "\n=== Linear System Solution ===\n"
gfortran -o LINSOL.o LINSOL.FOR -lslatec
./LINSOL.o

# EIGSOL.FOR
echo -e "\n=== Eigenproblem Solution ===\n"
gfortran -o EIGSOL.o EIGSOL.FOR -lslatec
./EIGSOL.o

Please supply contents of EIGSOL.mat and LINSOL.mat data files