[marye]

Hi,

I need to create a UDF function. I've written a program in C but the result is not correct.

So I've decided to check each step. And I've realised that this simple program :

#include"udf.h"
#include"mem.h"
#include"stdio.h"

DEFINE_PROPERTY(cell_visco, cell, thread)

{


int I[3][3];
int i,j;

real mu_lam;
real vitesse = C_U(cell, thread);

I[0][0] = 1;
I[0][1] = 2;
I[0][2] = 2;
I[1][0] = 2;
I[1][1] = 2;
I[1][2] = 2;
I[2][0] = 2;
I[2][1] = 2;
I[2][2] = 1;

for(i=0; i<3; i++)
{
for (j=0; j<3; j++)
printf("I[%d][%d] = %d \n", i , j, I[i][j]);

}

if (vitesse>0.000001)
mu_lam = 2.;
else
mu_lam = 40.;
}


return an incorrect matrix I :

I[0][0] = 1
I[0][1] = 2
I[0][2] = 2
I[1][0] = 2
I[1][1] = 1
I[1][2] = 2
I[2][0] = 0
I[2][1] = 2
I[2][2] = 1


If I change the values of the matrix I, the result printed in Fluent is incorrect for I[1][1] and I[2][0] but correct for the other terms.

If anyone could help me...
thank you so much!

[DoHander]

Your code is absolutely correct, here is a truncated version that will compile independently:

#include"stdio.h"

int main()
{

int I[3][3];
int i,j;

I[0][0] = 1;
I[0][1] = 2;
I[0][2] = 2;
I[1][0] = 2;
I[1][1] = 2;
I[1][2] = 2;
I[2][0] = 2;
I[2][1] = 2;
I[2][2] = 1;

for(i=0; i<3; i++)
{
for (j=0; j<3; j++)
printf("I[%d][%d] = %d \n", i , j, I[i][j]);

}
return 0;
}

and the results:
===============
C:\Users\Dol\Desktop\tste>a.exe
I[0][0] = 1
I[0][1] = 2
I[0][2] = 2
I[1][0] = 2
I[1][1] = 2
I[1][2] = 2
I[2][0] = 2
I[2][1] = 2
I[2][2] = 1

C:\Users\Do\Desktop\tste>
===============
Probably you have a problem in some other place. A suggestion will be to use Message function instead of printf, Message is a Fluent's own replacement for printf.

Hope this will help,

Do

[marye]

Hi,

Thank you for your answer.

I tried with the function Message but I have this error :

CX_Message : no function prototype

And in the user guide, I found "

It is recommended that you use

Message instead of printf in compiled UDFs (UNIX only)"

But I do not use UNIX...

Moreover if I write
int main() in my program, it doesn't work anymore...