Re: Call a C program from RPG with variables & a return

Charles,
Thank you for your suggestion.  I was using the SQL set function after calculating the total for three months:
$Tot03 = ($AvgH(1) * $AvgH(2)  * $AvgH(3))

SET :$Geo03  =  :$Tot03 ** (1/:$Root03);  

And that works fine.  When I try it with 12 month's, the result field is not large enough (set to 63P) and the program errs.  Same happens with:
$Tot12 = ($AvgH(1) * $AvgH(2)  * $AvgH(3) *                      $AvgH(4) * $AvgH(5)  * $AvgH(6) *                      $AvgH(7) * $AvgH(8)  * $AvgH(9) *                      $AvgH(10) * $AvgH(11)  * $AvgH(12))                    ** (1/12); 
I think I need to use 'C' because if I declare the result field as "double" I do not have the restriction I do in RPG.                                Regards, Stephen M. Mooney

From: Charles Wilt <charles.wilt@xxxxxxxxx>
To: Bare Metal Programming IBM i (AS/400 and iSeries) <c400-l@xxxxxxxxxxxx>
Sent: Wednesday, February 17, 2016 8:49 AM
Subject: Re: [C400-L] Call a C program from RPG with variables & a return

Why bother with C?

RPGLE can do it quite easily.

gMean = (a*b*c*d*e*f*g*h*i*j*k*l) ** (1/12);

Charles



On Tue, Feb 16, 2016 at 5:07 PM, Stephen Mooney <stephenmmooney@xxxxxxxxx>
wrote:

Greetings,
I am looking for some example 'C' code that will allow me to pass 12
numeric variables from an SQLRPGLE program to a 'C' program that will
calculate the geometric mean for them and return the value to the SQLRPGLE
program.
I found an example where an RPG program will pass two character fields to
a 'C' program which will concatenate and return them, however I know
nothing of 'C', its syntax, or setting it up with an 'int' or 'void' to get
my example to do what I want.
Currently, this is the 'C' code example I am working with:
#include <stdio.h>

                                      /* Main program. */


  int main(int argc, char *argv[])
                      {

                                                            /* Display
parameters sent to the program. */
        printf("Incoming parameter 1 = %s\n", argv[1]);
                          printf("Incoming parameter 2 = %s\n", argv[2]);

                                                              /*
Concatenate the two incoming parameters into the third parameter. */
                strcpy(argv[3],argv[1]);
                                    strcat(argv[3],argv[2]);

                                                                        /*
End of program.  Returning with concatenation of parameters 1 and 2 into
parameter 3. */  return;

                                                    }

I have found a 'C' program example that calculates the geometric mean I am
looking for, but it is set up as follows:
    #include<stdio.h>                                #include<math.h>
                            int main(void)
  {                                                    //
((X1)(X2)(X3)........(XN))1/N                double
x1=2,x2=4,x3=6,x4=7,x5=6;                double x,N=5;
                x=(x1*x2*x3*x4*x5);
x=pow(x,(1/N));                                  printf("Geometric Mean for
Xn: %lf",x);          return 0;                                    }

I believe I would need to set up x1=argv[1], x2=argv[2] and so on, but I
do not believe I am setting up the variables correctly to pass back what I
am looking for.
Any suggestions would be greatly appreciated.  Thanks. Regards, Stephen
Mooney
--
This is the Bare Metal Programming IBM i (AS/400 and iSeries) (C400-L)
mailing list
To post a message email: C400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/c400-l
or email: C400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/c400-l.