CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > EnSight

data sets comparison, subtraction: cumbersome

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   March 6, 2014, 11:43
Default data sets comparison, subtraction: cumbersome
  #1
Senior Member
 
François Grégoire
Join Date: Jan 2010
Location: Laval University, Canada
Posts: 366
Rep Power: 8
macfly is on a distinguished road
Hi,

I'm playing with a trial version of Ensight and I find it very cumbersome to compare 2 different cases. Here is how I do it, please tell me if there is a simpler way:

1. Open 2 cases in 2 different viewports.

2. Create a 3rd viewport.

3. Copy all parts of Case 2 and and associate the copied parts to the 3rd viewport (see tutorial EnSight10 FLOW-3D Part 1 at about 7:20 to learn how to associate parts to viewports, plot different variables of the same Case in different viewports...)

4. Select original parts of Case 2 and Create a Calculator => Predefined Functions => create a CaseMap of a scalar or a variable from Case 1 onto original parts of Case 2. Let's say I named my CaseMap "Tcase1", corresponding to temperature from Case 1 mapped onto original parts of Case 2:
- Variable name: Tcase1
- Expression: CaseMap(1,TEMPERATURE,1)

5. Select original parts of Case 2 and Create a Calculator => Build your own functions => create a variable with an expression containing the CaseMap, for example the difference between temperature of Case 2 and temperature from Case 1:
- Variable name: deltaT
- Expression: TEMPERATURE-Tcase1

6. Plot the new variable on the 3rd viewport that contains all the copied parts from Case 2.

That's it, cumbersome isn't it?
macfly is offline   Reply With Quote

Old   March 7, 2014, 12:13
Default data sets comparison, subtraction: cumbersome
  #2
Member
 
kevincolburn's Avatar
 
Kevin Colburn
Join Date: Mar 2009
Posts: 73
Rep Power: 8
kevincolburn is on a distinguished road
Francoise,

That is certainly one way to compute the difference between variables, and be able to display the original (case1), the subsequent (case2), and the difference all at the same time in the session of EnSight.

However, viewports are separate from cases, so the multiple viewports are not necessarily needed, if all you are trying to do is subtract the values. So, more precisely, if all you are trying to do is subtract the values, then all you need are steps 4 & 5 (CaseMap, then subtract).

If you are attempting to view both the original, the second case, and the difference all at one time, then the steps that you outline are fair. All can be captured in a macro, so that it is only a single click to perform all of that, if you are looking to simplify that process for your use.

Let us know if you have any questions, or would like additional information, we are here to help.

-Kevin (kevin@ceisoftware.com)
__________________
Kevin Colburn
Computational Engineering International, Inc.
www.ceisoftware.com
kevin@ceisoftware.com
kevincolburn is offline   Reply With Quote

Old   March 7, 2014, 15:41
Default
  #3
Senior Member
 
François Grégoire
Join Date: Jan 2010
Location: Laval University, Canada
Posts: 366
Rep Power: 8
macfly is on a distinguished road
Hi Kevin,

Thanks for the reply. You guys at CEI answer quickly to emails and forum questions, it's appreciated.

Yes, I thought about writing a macro, but for it to be versatile I guess I would have to find how to program some loop through all parts of a given model, and I don't want to go on that journey now.

P.S. in french Francoise is the feminine version of Francois, careful with that!
macfly is offline   Reply With Quote

Old   March 7, 2014, 15:49
Default
  #4
Member
 
kevincolburn's Avatar
 
Kevin Colburn
Join Date: Mar 2009
Posts: 73
Rep Power: 8
kevincolburn is on a distinguished road
C'est ma faute. (A long time ago I was taught Canadian French, growing up only a few hrs from montreal).

Yes, the macro method is bit more involved, and would be useful if you were doing it a lot. But, for the casual use, it can be too much. The quick way would be do it once, save the commands that were journalled, and then just replay them again (this is not completely generic, but could be used to save time).

Let us know if you need anything else.

-Kevin
__________________
Kevin Colburn
Computational Engineering International, Inc.
www.ceisoftware.com
kevin@ceisoftware.com
kevincolburn is offline   Reply With Quote

Old   March 28, 2014, 18:21
Default
  #5
Senior Member
 
François Grégoire
Join Date: Jan 2010
Location: Laval University, Canada
Posts: 366
Rep Power: 8
macfly is on a distinguished road
I never got to be able to compare two cases side-by-side, each with their own independent legend in their respective viewport.

It's convenient in other softwares to be able to see, for example, the Case 1 in its own viewport, with its own temperature range and its own legend. Then the same for Case 2 in an other viewport.

In Ensight, if 2 cases are loaded, the range of the variable 'temperature' comprises the min and max of all the cases and there is no (easy) way to see what's the range of Case 1 and the range of Case 2.

Is there a way to do that? It looks as if 2 cases have the same nomenclature for all the variables, Ensight lumps all the values under the same variable for all variables. (hope my explanations are clear)
macfly is offline   Reply With Quote

Old   March 28, 2014, 20:33
Default
  #6
Member
 
kevincolburn's Avatar
 
Kevin Colburn
Join Date: Mar 2009
Posts: 73
Rep Power: 8
kevincolburn is on a distinguished road
When you load your second, or subsequent case, just specify in the "Create new viewport for this case". This will setup the new case in its own viewport without any other work.

If the variables are named the same, EnSight tries to make things simple, and provide one variable. As they are the same variable, this simplifies things by being able "select both cases", and "color by temperature", rather than having to ask to color case 1 by temperature, and then case 2 by temperature.

If the ranges of each case are different, and you want to have different legend ranges for each case, that is very easy to do. Simply copy the variable over to a new name : Temp_Case2 = Temperature. Now, color Case 2 by "Temp_Case2", and you then have a second legend, and adjust that range separately.

Please feel free to use the normal support mechanism (email support@ceisoftware) or your local EnSight support representative.

Regards,
Kevin
__________________
Kevin Colburn
Computational Engineering International, Inc.
www.ceisoftware.com
kevin@ceisoftware.com
kevincolburn is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
need wind turbine data for cfd validation Reggio Main CFD Forum 0 September 9, 2012 11:30
comparison of numerical data HaKu Main CFD Forum 1 June 29, 2011 23:07
Modelling of a foil and comparison with NACA data Tom CFX 5 December 9, 2006 15:10
Experimental data for comparison Dr. H.K.Narahari Main CFD Forum 0 August 22, 2000 06:23
need sample post CFD data sets Joe Conti Main CFD Forum 0 April 17, 2000 15:38


All times are GMT -4. The time now is 13:59.