Operating at cell level

[griffin28]

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Hi all!
I'm working with a 2D cartesian mesh (a normal and simple one) using the python CLI interface. All variables are scalars zone-centred.

I would like to be able to operate at cell level, e.g. do a looping over all cells in the mesh, maybe a double one of the kind (a typical C/FORTRAN one):

for j in range(ny):
   for i in range(nx): 

      statements --> pres(i,j) = A(i,j)
      ....

   # endfor i
# endfor j

Or maybe something like this:

for j in range(zoneid):

      statements --> pres(j) = A(j)
      ....

# endfor j

How could I do that? Where can I start from? Any idea or example will be appreciated!

Best regards!

[griffin28]

Ernesto you can use ZonePick and do something like:

for j in range(ny):
   for i in range(nx):
           ZonePick(x=i, y=j, vars=("varName1", "varName2"))  # can use coord = (i,j,0)
           pickOutput = GetPickOutputObject()
           zoneFloat = float(pickOutput['zone_id'])
           var1Value= float(pickOutput['varName1'])
           var2Value = float(pickOutput['varName2'])

Here's documentation of the Zone Pick Function

Here's a reference to VisIt scripting in general

[markcmiller86-visit]

Thanks a lot Kevin for your fast response! I have now an additional question.

>for j in range(ny): > for i in range(nx): > ZonePick(x=i, y=j, vars=("varName1", "varName2")) # can use coord = (i,j,0) > pickOutput = GetPickOutputObject() > zoneFloat = float(pickOutput['zone_id']) > var1Value= float(pickOutput['varName1']) > var2Value = float(pickOutput['varName2'])

This is really nice to operate between cells. But, what about saving results in a new or different scalar-expression. E.g. I'm working with var1Value and var2Value, and want to save results in a different var3Value to do then a pseudocolor plot. Best! El vie., 2 oct. 2020 a las 13:29, Kevin Griffin via visit-users (< [email protected]>) escribió:

…

Ernesto you can use *ZonePick* and do something like: for j in range(ny): for i in range(nx): ZonePick(x=i, y=j, vars=("varName1", "varName2")) # can use coord = (i,j,0) pickOutput = GetPickOutputObject() zoneFloat = float(pickOutput['zone_id']) var1Value= float(pickOutput['varName1']) var2Value = float(pickOutput['varName2']) Here's documentation of the Zone Pick Function <https://visit-sphinx-github-user-manual.readthedocs.io/en/develop/cli_manual/functions.html?highlight=zonepick#zonepick> Here's a reference to VisIt scripting in general <https://visit-sphinx-github-user-manual.readthedocs.io/en/develop/tutorials/Scripting.html> — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <https://github.com/visit-dav/live-customer-response/issues/155#issuecomment-702831565>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AOLAYZGJDJIBN66ZSYWVT6LSIX5YBANCNFSM4SB4AOSQ> . -- VisIt Users Wiki: http://visitusers.org/ Frequently Asked Questions for VisIt: https://wci.llnl.gov/simulation/computer-codes/visit/FAQ.html To Unsubscribe: send a blank email to ***@***.*** More Options: https://elist.ornl.gov/mailman/listinfo/visit-users

[griffin28]

In that case you don't need to loop through each cell as VisIt will apply the new expression across the entire dataset. You will need to do something like:

DefineScalarExpression("varName3", "varName1 + varName2")

There are a number of math operators and functions you can use in expressions. Look here for more details.