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I need help in programing in FOTRAN 90

  1. May 7, 2012 #1
    Hi
    I have written a program in FOTRAN for solving special system called Tridiagonal system
    has 5 equation
    I'm in the learning stage of FOTRAN 90
    and this my program::
    Please help me

    program triiagonal
    implicit none
    real, dimension A(5,5),B(5,5),f(5),X(5)
    integer::n,i,j,m,k,l,s1,s2
    print*,"input the number of element(n)"
    read*,n
    do i=1,n
    do j=1,n+1
    print*,"input the matrix a(i,j)"
    read*,A(i,j)
    end do
    end do
    m=n*(n-1)/2
    do i=2,n
    do k=1,n-1
    if(A(i,j)/=0)then
    do j=1,n+1
    A(i,j)=A(i,j)-f(i,k)*A(j,k)
    end do
    else
    do l=i-1,i-1
    do j=1,n+1
    b(i,j)=a(i,j)
    a(i,j)=a(i+1,j)
    a(i+1,j)=b(i,j)
    end do
    end do
    end if
    do i=n,1,-1
    do j=i+1,n
    s2=s2+A(i,j)*(j)
    end do
    s1=a(i,n+1)
    x(i)=(s1-s2)/a(i.i)
    end program triiagonal


    this my error::
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(3): error FOR3852: syntax error detected between DIMENSION and A
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(10): error FOR3701: symbol A is not a variable
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(18): error FOR3712: symbol A is not an array
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(24): error FOR3712: symbol A is not an array
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(25): error FOR3712: symbol A is not an array
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(29): error FOR3541: duplicated DO index variable - I
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(34): error FOR3251: symbol I is not a derived type detected between % and I
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(36): error FOR3597: missing 3 END DO statements
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(36): error FOR2290: implicit type for X
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(36): error FOR2290: implicit type for F
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(36): error FOR2290: implicit type for B
    C:\Documents and Settings\eXtreme\Desktop\New Folder\ffff\fff.f90(36): error FOR2290: implicit type for A

    Your help would be appreciated.
    Thanks
     
  2. jcsd
  3. May 7, 2012 #2
    Replace this:
    Code (Text):

    real, dimension A(5,5),B(5,5),f(5),X(5)
     
    with this:
    Code (Text):

    real, dimension(5,5) :: A,B
    real, dimension(5) :: f,X
     
    and try again.
     
  4. May 8, 2012 #3
    ooooooh no ....... the same errors !!?
     
  5. May 8, 2012 #4
    please repost source, use code tags
     
  6. May 8, 2012 #5
    Code (Text):
    program  tridiagonal   
    implicit none
    real, dimension  A(5,5),B(5,5),f(5),X(5)
    integer::n,i,j,m,k,l,s1,s2
    print*,"input the number of element(n)"
    read*,n
    do i=1,n
     do j=1,n+1
      print*,"input the matrix a(i,j)"
      read*,A(i,j)
     end do
    end do
      m=n*(n-1)/2
    do i=2,n
     do k=1,n-1
     if(A(i,j)/=0)then
     do j=1,n+1
     A(i,j)=A(i,j)-f(i,k)*A(j,k)
     end do
     else
    do l=i-1,i-1
     do j=1,n+1
     b(i,j)=a(i,j)
     a(i,j)=a(i+1,j)
     a(i+1,j)=b(i,j)
     end do                              
    end do
    end if
    do i=n,1,-1
    do j=i+1,n
      s2=s2+A(i,j)*(j)
     end do
     s1=a(i,n+1)
     x(i)=(s1-s2)/a(i.i)

    end program  tridiagonal
     
    my program in attachment ........
     

    Attached Files:

    • fff.zip
      fff.zip
      File size:
      425 bytes
      Views:
      113
  7. May 8, 2012 #6
    o.k., so, you did not implement what I suggested...no wonder you are getting the same errors!
     
  8. May 8, 2012 #7
    No No ...... This my .... i implemented what you suggested :)
    But i am getting the same errors ,,,,,,, so i post the program before Modifying >>
    ^_^
    Please help me ,,,
    Bye
     
  9. May 8, 2012 #8

    Mark44

    Staff: Mentor

    Then what does your code look like now?
     
  10. May 8, 2012 #9
    jonephy:

    please try to be more careful and let it be you who does the double checking of things...we are here to guide you, not to do the work for you.

    please double check what you are doing and make sure you implemented the changes I suggested earlier.

    also, you have a mess with your do-loops and the loop variables....step back and double check all that; there are also a couple of "end do" missing.
     
  11. May 9, 2012 #10
    Thanks all
    Ok, i will be more careful
    and i will trying to fix all problems in my program
    >>>>
    Good Bye
     
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