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Old   June 19, 2017, 05:30
Default udf source
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Hello,

I have a question and I will like if anyone can help me to write the following DEFINE_SOURCE:
I inform you that the values of T_mean and Time is in a txt file named result.txt.

I want to write an udf program that uses the found values of the text file.
I ran the progame and I did not find any errors but the program does not give me the values of
T_mean and Time. Help me please.


DEFINE_SOURCE(Source_AIR, c, t, dS, eqn)
{
real source, Time,T_mean;
FILE *pFile;
pFile=fopen("c:/result.txt","r");
fscanf(pFile,"%g %g\n",&Time,&T_mean);
fclose(pFile);
source =32*T_mean*Time;
dS[eqn] = 0.0;
return source;
}

Last edited by fersim; June 19, 2017 at 13:39.
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Old   June 19, 2017, 08:38
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-You don't give any value to T_mean

-Also this equation is odd:
TEMP=T_Mean;
source =32*T_Mean*TEMP/TIM;

T_mean*TEMP is the same as T_mean^2
Why do you even need the TEMP?

-You have not defined the T_Moyenne inside the DEFINE_SOURCE.

-You should remove the semicolon ';' from inside of fscanf(pFile,"%g ;%g\n" and fprintf(pFile,"%g ;%g\n"

-fscanf( is missing the last bracket ')'
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Old   June 19, 2017, 09:08
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thank you for your replay

For this Source term, I want open file text (in mu case result.txt), in this file they have a value, for exemple 30 299. (30 is 30 sec, and 299 is temperature).

for DEFINE SOURCE, I want open result.txt and read 30 as time and 299 as temperture.

Tahnk you.

DEFINE_SOURCE(Source_AIR, c, t, dS, eqn)
{
real source, Time,T_mean;
FILE *pFile;
pFile=fopen("c:/result.txt","r");
fscanf(pFile,"%g %g\n",&Time,&T_mean);
fclose(pFile);
source =32*T_mean*Time;
dS[eqn] = 0.0;
return source;
}
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Old   June 19, 2017, 09:19
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still:

-fscanf( is missing the last bracket ')'
-T_Moyenne
-are you sure about that source-equation?
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Old   June 19, 2017, 09:30
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My problem is not in the equation or in the bracket (. but how can I read a file txt and load some variables (Time and Time) in the DEFINE SOURCE
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Old   June 19, 2017, 09:45
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Your problem was also the bracket. UDF do not work, if the code is wrong.

Do you need the "\n" when using fscanf();?

You could also try %f in your fscanf(); or are you using double precision?
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Old   June 19, 2017, 10:21
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not necessery to put \n or double double precision, I want juste read a text file
and calculate source =32*T_mean*Time. the values of Time and T_mean finded in the file text.

I want to have any solution to read these two values from a text file.
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