Hi,

i wrote the following UDF to write some simple data on an external file:

/*****UDF for output*****/

#include "udf.h"

DEFINE_ON_DEMAND(output)

{

Domain *d;

real x[ND_ND];

real x0, y0, z0, u, v, w;

real p, mut;

int time;

char *filename;

FILE *fp;

Thread *t;

cell_t c;

d = Get_Domain(1);

time = N_TIME;

filename = "data.txt";

fp = fopen(filename,"w");

thread_loop_c(t,d)

{

begin_c_loop(c,t)

{

C_CENTROID(x,c,t);

ND_SET(x0, y0, z0, x[0], x[1], x[2]);

ND_SET(u, v, w, C_U(c, t), C_V(c, t), C_W(c, t));

p = C_P(c,t);

mut = C_MU_T(c,t);

fprintf(fp, "%14.12f %14.12f %14.12f ", x0, y0, z0);

fprintf(fp, "%18.16f %18.16f %18.16f %18.16f %18.16f\n", u, v, w, p, mut);

}

end_c_loop(c,t)

}

fclose(fp);

}

Now, i'd like to modify filename to handle the the current number of time steps, i.e.

data-2000.txt

data-3000.txt

and so on, but i'm not able to do so. Actually i think that the only line which has to be modified is

filename = "data.txt";

but i don't know how because all i know about c is coming from the fluent udf manual. Any help is really appreciated.

Thanks

hello paolo

sprintf() will do the job, e.g.:

const char base[] = "data-"; char filename [10]; int number = RP_Get_Integer("time-step"); sprintf(filename, "%s%d", base, number);

you may check this with: printf("filename = \"%s\"\n", filename);

cheers max

Thanks max for your help but i'm not able to let it work.

Moreover sprintf seems not be recognized...maybe it is because i'm interpreting the udf

Somewhere i also find the itoa command but i really don't know how to use it. Anyway, thanks again for your help.

All i can say is that sprintf works nicely in compiled udf mode. Give it a try and let me know if the problem persists.

max