module globals

    implicit none
    save
    
    integer, parameter:: dble = kind(1d0)

end module globals


program SimpleFileIO
    use globals
    implicit none
    
    !variable declarations
    integer, parameter:: T=5
    real(dble) xvect(T), yvect(T) 
    real(dble) xmat(T,T), y1mat(T,T), y2mat(T,T)
    real(dble) xvar
    integer i,j
    
    !variable initializations 
    xvar = 1.0d0
    xvect = (/(sqrt(xvar + i),i=0,T-1)/)
    xmat = reshape((/((xvar+i)**(1/3.0d0), i=0,T*T)/), (/T,T/))
    
    !Writing a 1-dimensional array to a file
    open(11,file = "data.txt")
    do i =1,T           
        write(11,'(f8.4)') xvect(i)
    end do
    close(11)
    
    !Reading data from a file into a 1-dimensional array
    open(11,file = "data.txt")
    read(11,*) yvect
    close(11)

    !Writing 2 2-dimensional arrays to a file
    open(12,file = "data2.txt")
    write(12,'(f8.4)') ((xmat(i,j),i=1,T),j=1,T)
    write(12,'(f8.4)') ((xmat(i,j),j=1,T),i=1,T)
    close(12)
    
    !Reading data from a file into 2 2-dimensional arrays
    open(12,file = "data2.txt")
    read(12,*) y1mat, y2mat
    close(12)
    
    !Printing to screen
    print '(a,100f8.4,:)', "xvect=", (xvect(i), i=1,T)
    print '(a,100f8.4,:)', "yvect=", (yvect(i), i=1,T)
    print *, "xmat"
    do i=1,T
        print '(100f8.4,:)', (xmat(i,j),j=1,T)
    end do
    print *, "y1mat"
    do i=1,T
        print '(100f8.4,:)', (y1mat(i,j),j=1,T)
    end do
    print *, "y2mat"
    do i=1,T
        print '(100f8.4,:)', (y2mat(i,j),j=1,T)
    end do
    close(12)


end program SimpleFileIO