How to check value at every cell when applied udf

Chhotelal1234 · July 22, 2023, 14:25

Can I check our UDF line by line in fluent whether is it correct or not?
Can I get the value at every iteration whatever equation add in the UDF so that we can easily check it either our UDF is working properly or not?
Can I add the breaks in particular line in UDF. So that we can check it?

Siba11 · July 23, 2023, 10:06

'Yes' to all three of your questions.
The fluent compiler checks your UDF line by line and displays any errors present in it.
You can print whatever value you want using the 'Message' statement.
And yes, you can insert 'break' commands wherever you want. It's a good programming practice when you're trying to debug your code.

Chhotelal1234 · July 23, 2023, 10:49

Thank you for your reply. but the break command could not be used in the UDF reason is that the UDF code is called from the solver, and it operates within a specific context set by the solver. Using break to exit a loop would disrupt the solver's control flow and could lead to unexpected behavior or crashes.
There are any method to check the UDF code?

AlexanderZ · July 23, 2023, 20:49

1. You may print into console variables to check which part of code works well. Message() macro
2. You may hook fluent.exe process from visual studio (for windows) and debug regularly

Chhotelal1234 · July 24, 2023, 01:50

Dear AlexanderZ,
Could you please describe the second option how can I use it. and give a example.

AlexanderZ · July 25, 2023, 20:55

The simplest way to debug Fluent UDF

July 22, 2023, 14:25	How to check value at every cell when applied udf	#1
Chhotelal1234 Member Chhotelal Join Date: Jun 2023 Posts: 31 Rep Power: 3	Can I check our UDF line by line in fluent whether is it correct or not? Can I get the value at every iteration whatever equation add in the UDF so that we can easily check it either our UDF is working properly or not? Can I add the breaks in particular line in UDF. So that we can check it?

July 23, 2023, 20:49		#4
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	1. You may print into console variables to check which part of code works well. Message() macro 2. You may hook fluent.exe process from visual studio (for windows) and debug regularly __________________ best regards ****************************** press LIKE if this message was helpful

July 25, 2023, 20:55		#6
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	The simplest way to debug Fluent UDF __________________ best regards ****************************** press LIKE if this message was helpful

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
A UDF to calculate energy per a cell and then returns new CO2 content in a cell.	visitor	Fluent UDF and Scheme Programming	54	April 11, 2021 23:29
UDF in case with DPM modle	POSTHU	Fluent UDF and Scheme Programming	0	March 3, 2021 08:21
Fluent UDF wrong number of cells in parallel - correct in serial	dralexpe	Fluent UDF and Scheme Programming	7	May 17, 2018 09:26
how to comliled UDF on one of two fluid cell zones	lshwanbb	Fluent UDF and Scheme Programming	0	December 16, 2017 21:41
Cells with t below lower limit	Purushothama	Siemens	2	May 31, 2010 22:58

July 23, 2023, 10:06		#2
Siba11 Member Odisha Join Date: Jan 2020 Posts: 59 Rep Power: 6	'Yes' to all three of your questions. The fluent compiler checks your UDF line by line and displays any errors present in it. You can print whatever value you want using the 'Message' statement. And yes, you can insert 'break' commands wherever you want. It's a good programming practice when you're trying to debug your code.

July 23, 2023, 10:49		#3
Chhotelal1234 Member Chhotelal Join Date: Jun 2023 Posts: 31 Rep Power: 3	Thank you for your reply. but the break command could not be used in the UDF reason is that the UDF code is called from the solver, and it operates within a specific context set by the solver. Using break to exit a loop would disrupt the solver's control flow and could lead to unexpected behavior or crashes. There are any method to check the UDF code?

July 24, 2023, 01:50		#5
Chhotelal1234 Member Chhotelal Join Date: Jun 2023 Posts: 31 Rep Power: 3	Dear AlexanderZ, Could you please describe the second option how can I use it. and give a example.