Maximal number of boundary patches

laurentD · July 12, 2016, 09:22

Hi,
i will need to define a lot of patches for my model (~1000).
But before to define them, and spend an afetrnoon doing that, i guess there is a maximal limit for this number of patches.
Does anybody know more about such a limit ?
Thanks
Laurent

alexeym · July 12, 2016, 09:35

Hi,

It is maximum value label type can hold and as

Code:

A label is an int32_t or int64_t as specified by the pre-processor macro WM_LABEL_SIZE

and it is 2^(N - 1) - 1.

laurentD · July 13, 2016, 09:26

Hi Alexey,
i am not sure to understand your answer.
You are saying that if my machine is a 64bit one,
the maximal number of patches is 2^(64 - 1) - 1 = 9e+18,
And if it is 32 bit one, this limit is : 2^(32 - 1) - 1 = 2e+09 ?
Please confirm this information if it is true.
Thank you very much,
Laurent

alexeym · July 13, 2016, 13:19

Hi,

That is right. For 32-bit integers it is 2147483647, for 64-bit integers it is 9223372036854775807. Patches are stored in the data structure PtrList and its size is stored in the field size_ of type label (https://github.com/OpenFOAM/OpenFOAM.../UList/UList.H).

So theoretically, you could store up to 2^(N - 1) - 1 items in PtrList.

laurentD · July 18, 2016, 09:14

Hi,
i have tried to use gmshToFoam with a msh including nearly 800 patch names and it crashes with a fatal error when the patch number pass over 99.
Like if there is a limit fixed to 100...
Anyone know where i can modify it ?
Laurent

alexeym · July 18, 2016, 09:32

Hi,

It would be great to see original output (when gmshToFoam crashes) and test case.

laurentD · July 18, 2016, 09:34

Hi,

http://www.cfd-online.com/Forums/ope...tml#post610015

alexeym · July 18, 2016, 09:37

And the test case? Crash output looks like corrupted msh file. Surely one can generate msh file with 800 physical groups, yet, it will take time.

laurentD · July 18, 2016, 09:55

The msh file is too big to be sent...
Have you got a mail adress where i can send it ?

laurentD · July 18, 2016, 10:46

This is the related part of the msh file :

Code:

 2 94 "PEAU_EXT_007_02"
2 95 "PEAU_EXT_007_11"
2 96 "PEAU_EXT_007_08"
2 97 "PEAU_EXT_008_04"
2 98 "PEAU_EXT_008_03"
2 99 "PEAU_EXT_008_06"
2 100 "PEAU_EXT_008_01"
2 101 "PEAU_EXT_008_12"
2 102 "PEAU_EXT_008_07"

laurentD · July 18, 2016, 11:09

Ok i'm sorry...
i have found what was wrong on the msh file.
When the numbering of the patches pass over 99, the writing format is wrong.
Now my model is working with 1661 patches.
Thank you very much for your help Alexey.
Your remarks have been very helpful to help me to find the problem.
Have a good day.

July 12, 2016, 09:22	Maximal number of boundary patches	#1
laurentD Senior Member Laurent DASTUGUE Join Date: May 2014 Location: Chartres, France Posts: 122 Rep Power: 11	Hi, i will need to define a lot of patches for my model (~1000). But before to define them, and spend an afetrnoon doing that, i guess there is a maximal limit for this number of patches. Does anybody know more about such a limit ? Thanks Laurent

July 12, 2016, 09:35		#2
alexeym Senior Member Alexey Matveichev Join Date: Aug 2011 Location: Nancy, France Posts: 1,932 Rep Power: 38	Hi, It is maximum value label type can hold and as Code: A label is an int32_t or int64_t as specified by the pre-processor macro WM_LABEL_SIZE and it is 2^(N - 1) - 1.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
sliding mesh problem in CFX	Saima	CFX	46	September 11, 2021 07:38
[OpenFOAM.org] OF2.3.1 + OS13.2 - Trying to use the dummy Pstream library	aylalisa	OpenFOAM Installation	23	June 15, 2015 14:49
Question about heat transfer coefficient setting for CFX	Anna Tian	CFX	1	June 16, 2013 06:28
Error finding variable "THERMX"	sunilpatil	CFX	8	April 26, 2013 07:00
Convective Heat Transfer - Heat Exchanger	Mark	CFX	6	November 15, 2004 15:55

July 13, 2016, 09:26		#3
laurentD Senior Member Laurent DASTUGUE Join Date: May 2014 Location: Chartres, France Posts: 122 Rep Power: 11	Hi Alexey, i am not sure to understand your answer. You are saying that if my machine is a 64bit one, the maximal number of patches is 2^(64 - 1) - 1 = 9e+18, And if it is 32 bit one, this limit is : 2^(32 - 1) - 1 = 2e+09 ? Please confirm this information if it is true. Thank you very much, Laurent

July 13, 2016, 13:19		#4
alexeym Senior Member Alexey Matveichev Join Date: Aug 2011 Location: Nancy, France Posts: 1,932 Rep Power: 38	Hi, That is right. For 32-bit integers it is 2147483647, for 64-bit integers it is 9223372036854775807. Patches are stored in the data structure PtrList and its size is stored in the field size_ of type label (https://github.com/OpenFOAM/OpenFOAM.../UList/UList.H). So theoretically, you could store up to 2^(N - 1) - 1 items in PtrList.

July 18, 2016, 09:14		#5
laurentD Senior Member Laurent DASTUGUE Join Date: May 2014 Location: Chartres, France Posts: 122 Rep Power: 11	Hi, i have tried to use gmshToFoam with a msh including nearly 800 patch names and it crashes with a fatal error when the patch number pass over 99. Like if there is a limit fixed to 100... Anyone know where i can modify it ? Laurent

July 18, 2016, 09:32		#6
alexeym Senior Member Alexey Matveichev Join Date: Aug 2011 Location: Nancy, France Posts: 1,932 Rep Power: 38	Hi, It would be great to see original output (when gmshToFoam crashes) and test case.

July 18, 2016, 09:34		#7
laurentD Senior Member Laurent DASTUGUE Join Date: May 2014 Location: Chartres, France Posts: 122 Rep Power: 11	Hi, http://www.cfd-online.com/Forums/ope...tml#post610015

July 18, 2016, 09:37		#8
alexeym Senior Member Alexey Matveichev Join Date: Aug 2011 Location: Nancy, France Posts: 1,932 Rep Power: 38	And the test case? Crash output looks like corrupted msh file. Surely one can generate msh file with 800 physical groups, yet, it will take time.

July 18, 2016, 09:55		#9
laurentD Senior Member Laurent DASTUGUE Join Date: May 2014 Location: Chartres, France Posts: 122 Rep Power: 11	The msh file is too big to be sent... Have you got a mail adress where i can send it ?

July 18, 2016, 11:09		#11
laurentD Senior Member Laurent DASTUGUE Join Date: May 2014 Location: Chartres, France Posts: 122 Rep Power: 11	Ok i'm sorry... i have found what was wrong on the msh file. When the numbering of the patches pass over 99, the writing format is wrong. Now my model is working with 1661 patches. Thank you very much for your help Alexey. Your remarks have been very helpful to help me to find the problem. Have a good day.