IMSL Exponent Graphics: Instructions: Fortran (f77)

Setting the Exponent Graphics Working Environment for Fortran (f77)

To use Exponent Graphics, you must set several UNIX environment variables. These settings may adversely interact with settings needed for other UNIX applications. The instructions below provide a strategy for avoiding these interactions.

You start a new shell before you use IMSL Exponent Graphics, modify the environment, run the programs, and exit the shell before working with other software. You can start a new shell either by opening a new window on an X terminal or by issuing the UNIX csh command. These instructions assume that you are using the C shell (csh), which is the default for University of Delaware users.

Start a new C shell by typing at the C shell prompt (%),

csh

Set the necessary environment variables for Exponent Graphics by typing at the C shell prompt (%),

source /opt/lib/ipt_1.2/ipt/bin/iptsetup.csh

Add the location for the X11 load library by typing at the C shell prompt (%),

setenv LD_LIBRARY_PATH /opt/X11R5/lib:${LD_LIBRARY_PATH}

Proceed to the compilation and execution steps for your program.

Important warning: These instructions may redefine values of environment variables you previously defined in your dotfiles (e.g., ".localenv" file). The most likely variables to have been changed are FC and FFLAGS. If these variables are not present in your dotfiles, you will be fine. However, if you need to preserve your standard settings for these variables when using IMSL Exponent Graphics, you must explicitly type your modifications after following the above instructions. If you need help or clarification, send e-mail to consult@udel.edu.

Compiling and Executing a Fortran (f77) Program

Having set up your working environment, you can now compile and execute Exponent Graphics programs. When you're done using the Exponent Graphics libraries, you should exit the current shell (or close the current window), thereby returning to your previous working environment.

Modify each Fortran source code file to fully specify the /opt/lib/ipt_1.2/include directory for any Exponent Graphics include file you use. For example, at the top of the main program and each subprogram in which the Exponent Graphics include file af.i is needed, add the line

include '/opt/lib/ipt_1.2/include/af.i'

Compile the Fortran program, linking to the Exponent Graphics link library. If your Fortran program is stored in the file filename.f, and you want to store the compiled version in a file named filename, type

f77 -o filename filename.f $LINK_EG

Run the program by typing,

filename

If prompted by the program for an output device, type 1 for the X terminal screen, or type ? to see the other choices.
A complete Fortran example is presented below.

Fortran (f77) Example Programs

Several example programs are stored in the directory /opt/lib/ipt_1.2/examples/eg/application_f77 for Fortran. The procedures above are illustrated next using modifications of the Fortran program named confill1.f. You can test whether you have set up your Exponent Graphics UNIX working environment properly by following the instructions below.

Start a new shell by typing,

csh

Set up the working environment as described above.
Use an editor (such as pico or vi) to create a file named example.f containing the following lines. Note that the include statement fully specifies the af.i include file.

      program main
      include '/opt/lib/ipt_1.2/include/af.i'
      integer    ncval, nx, ny
      parameter  (ncval=5, nx=11, ny=11)
c
      integer    istatus, iunit, new_plot
      real       ax, bx, ay, by, cfill_1
      external   cfill_1
c
      data iunit /0/
c
      ax   = -1.0
      bx   =  1.0
      ay   = -1.0
      by   =  1.0
      new_plot = 0
c                                  Setup the graphics database to 
c                                  contour plot
      istatus = af_tgrid_contour_function_plot (cfill_1, nx, ny, ax, bx,
     &             ay, by, ncval,
     &             af_no_label,
     &             af_contour_fill,
     &             0)

      new_plot = af3_contour_fill(ncval, new_plot)
c                                  Draw the plot and close graphics
      call af3_plot (iunit, 0)
      end
c
c
      real function cfill_1 (x, y)
      real       x, y
      cfill_1 = 2.0 - (x*x + y*y)
      return
      end

Compile the program and store the compiled version in a file named example by typing,

f77 -o example example.f $LINK_EG

Run the program by typing,

example

When prompted to specify an output device, type 1 to plot on the X terminal. The following graph will appear in a new window.

Click the mouse button in the new graph window to close. Now you are prompted again to specify an output device, type 11 to create a landscape postscript file. You will see the following error

 **** VNI-HOOPS error in ac_Pause has severity 3.
 **** There was an unexpected Hoops internal error -
 **** Nothing to wait for - no events are enabled
 **** Traceback =======>
 ****                   ac_Await_Event
 **** called from       ac_Await_Event
 **** called from       ac_Pause
 **** called from       ac3_plot
 **** called from       ac3_set

A new file is created called vnieg.ps regardless of the above error. You can print this file to any Postscript printer. Again you are prompted to specify an output device, type q to quit.

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