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tips:post [2012/11/21 22:09]
gag created
tips:post [2013/06/27 15:57] (current)
mschafer [ParaView] Tips: finished with what I could come up with
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 ==== ElmerPost ==== ==== ElmerPost ====
 +ElmerPost is the build-in post-processing tools of Elmer. ElmerPost reads result in Elmer Post type file (''​.ep''​). ​
 +=== Mesh deformation ===
 +For transient simulation, ElmerPost doesn'​t upgrade directly the mesh using the variable ''​Mesh Update''​. This has to be done manually, as follow.
 +First define a new variable to store the initial node coordinates. Enter in the command window (bottom of the main window):
 +math on = nodes
 +Then, in the command box of the timestep window:
 +math nodes = on + Mesh.Update(0:​2,​time($t)))
-==== ParaView ====+=== Useful scripts ​=== 
 +A file containing a matc function can be loaded and executed from the command window: 
 +source myscript.cmd 
 +Below is an example to construct a vector variable from 3 independent variable (useful for the [[solvers:​aiflow|AIFlow]] and [[solvers:​porous|Porous]] solvers):
 +proc tovector {} {
 +math {Velocity=0};​
 +math {k=size(Aiflow.1)[1];​}
 +math {Velocity(0,​0:​k-1)=Aiflow.1};​
 +math {Velocity(1,​0:​k-1)=Aiflow.2};​
 +math {Velocity(2,​0:​k-1)=0};​
 +math {Velocity_abs=sqrt(vdot(Velocity,​Velocity))};​
 +Save it in a file ''​makeVector.cmd''​ and execute it as follow:
 +load makeVector.cmd
 +==== ParaView ====
 +Elmer can export results in vtk or vtu formats. Since version 6128, this can be done automatically by setting the extension of the ''​Post File''​ to ''​vtu''​ in the Simulation section. Doing so, only a vtu output file is created (no ep file for ElmerPost). Alternatively,​ the following solver ​ can be added and run after all other solvers:
 +Solver 17
 +  Exec Solver = After TimeStep
 +  Exec Interval = 2
 +  Equation = "​result output"​
 +  Procedure = "​ResultOutputSolve"​ "​ResultOutputSolver"​
 +  Save Geometry Ids = Logical True ! add this line if you want to access boundaries in Paraview
 +  Output File Name = String "​myFile.vtu"​
 +  Output Format = String vtu
 +More information regarding this solver can be found in the [[http://​www.csc.fi/​english/​pages/​elmer/​documentation|Elmer documentation]]. More information regarding the Paraview software can be found [[http://​www.paraview.org|here]]. ​
 +=== Some tips when using Paraview: ===
 +  * **to visualize a variable only on one boundary condition** (for example bedrock):\\
 +- Add the line ''​Save Geometry Ids = Logical True''​ to your sif-file\\
 +- In paraview: Edit -> Find Data, find Cell, GeometryIDs is = ..., Run Extract Selection\\
 +- GeometryIDs usually start from 101\\  ​
 +  * **to calculate differences between different time-steps or runs** (condition: same mesh)\\
 +- Open both files\\
 +- Define for both files a Calculator to copy the variables that you want to calculate the difference from under another name, for example //Result ArrayName = temp1 (temp2)// for //Value = Scalars->​ temp//\\
 +- Select both Calculators:​ Filters -> Append Attributes\\
 +- Select the new AppendAttributes Item in the list (the one with the cube not the arrows)\\
 +- Define again a Calculator with Result ''​ArrayName=difftemp''​ and ''​Value= Scalars->​temp2 - Scalars->​temp1''​\\
 +- //​difftemp//​ contains now the difference\\
 +  * **to mark a certain location by a symbol**\\
 +- use Sources -> Sphere and define the origin as the location of your symbol\\
 +  * **to add a polyline on a 3D figure**\\
 +- save the (x,y,z) values of the points of the polyline in an ascii file (separated by ","​ or another symbol) with the ending "​.csv"​\\
 +- open this file as "comma separated values"​-file in paraview\\
 +- define the options (with headings or not etc.)\\
 +- use TableToPoints Filter\\
 +  * **Crossections of the ice-body**\\
 +- use "​Slice"​ or "​Clip"​\\
 +  * ** do not use ° in any text**, this leads to errors when saving/​loading a statefile.\\
 +If it has happened, open the statefile as ascii file and delete the ° and it should work again.\\
 +  *  **Iso-contours**\\
 +To draw only the lines, but not colored areas, switch "​Compute Normals off", that helps in most of the cases.\\
 +  * to **synchronize the view on different windows** (same zoom, view angle,​...)\\
 +- click right on the first window\\
 +- click on ''​link camera''​\\
 +- once the window ''​click on another window''​ appears click on the second window"​
tips/post.1353535752.txt.gz · Last modified: 2012/11/21 22:09 by gag
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