How to Compile MSES Software with Unexpected Syntax in Fortran?

[jasonbot]

Hello,

I'm trying to compile some software called MSES, its written by Mark Drela in some fortran flavour. I've successfully compiled a number of subroutines through make files but there is one subroutine giving me grief. It's called dplot.f.

It has a strage syntax I can't seem to work around:

     SUBROUTINE DPLOT
      INCLUDE 'STATE.INC'     
      INCLUDE 'MPLOT.INC'
C-----------------------------------------------------------
C     Reads in data file or reference profiles and plots them
C     superimposed on calculated profiles.  The profiles are
C     plotted in proper location on actual airfoil.
C-----------------------------------------------------------
C
      CHARACTER*40 FNAME, LINE, uname
      PARAMETER (IPRX=40,KPRX=240)
      DIMENSION XX(KPRX), YY(KPRX)
      DIMENSION APR(IPRX), XPR(IPRX), YPR(KPRX,IPRX), UPR(KPRX,IPRX)
      DIMENSION YADD(IPRX), YPRFAC(IPRX), UPRFAC(IPRX)
      DIMENSION DSPR(IPRX), THPR(IPRX), TSPR(IPRX)
      INTEGER KK(IPRX), NXPR(IPRX)
      LOGICAL LUPR, LTPR
c
      parameter (jprx=isx*200)
      dimension nsum$(jprx)
      dimension y$(jprx), u$(jprx), uinv$(jprx), udef$(jprx)

...

the dollar sign after a variable name, as in nsum$, makes no sense to me. Coming from MATLAB this wouldn't be a valid variable name and in my fortran compiler (tried both f77 and gfortran) it tells me a number of different errors about invalid forms and type disagreements. Removing the dollar signs gives errors relating to invalid declarations.

Does anyone have any idea how to fix my code?

 

[Solkar]

Use gfortran -fdollar-ok

Use gfortran with option -fdollar-ok:

Sample

c    file foo.f
      program foo
      real pi$
      parameter (pi$ = acos(-1.0)) 
      write(*,*) pi$   
      end program foo

Reproducing the error

gfortran foo.f
foo.f:3.14:

      real pi$                                                          
              1
Error: Invalid character '$' at (1). Use -fdollar-ok to allow it as an extension
foo.f:4.20:

      parameter (pi$ = acos(-1.0))                                      
                    1
Error: Invalid character '$' at (1). Use -fdollar-ok to allow it as an extension
foo.f:5.20:

      write(*,*) pi$                                                    
                    1
Error: Invalid character '$' at (1). Use -fdollar-ok to allow it as an extension

Fixing it

gfortran -fdollar-ok foo.f
echo $?
0

But despite this fix I would strongly discourage using non-standard names in self-written code.

Cheers, Solkar

 

[jasonbot]

Thank you Solkar.

What do you mean by using non standard names?

I'm new to fortran and wouldn't say I'm keen to learn it. I just need to use the programme for some work.

After using your suggestion it seemed to have compiled correctly although now I have some problems with additional modules with the error:

CHANGE = CHANGE .OR. (LMOD1(K,IP).XOR.LMOD(K,IP))
1
Error: Unknown operator 'xor' at (1)

I don't think ill bother investigating it because its a module I don't need.

 

[Solkar]

Thank you Solkar.
What do you mean by using non standard names?

Names which require tricking the compiler into eating them, like those ending with a "$" you asked for.

CHANGE = CHANGE .OR. (LMOD1(K,IP).XOR.LMOD(K,IP))
1
Error: Unknown operator 'xor' at (1)

I think intel's ifort has .xor. defined by default, but gfortran apparently doesn't.
Standard Fortran has

A .neqv. B

for XORing of logical A,B, and it's common wisdom that most compilers support

ieor(i,j)

for bitwise XORing of integer i,j.