
[Sponsors] 
October 28, 2008, 12:25 
Hi!
The warnings are from g

#21 
Assistant Moderator
Bernhard Gschaider
Join Date: Mar 2009
Posts: 3,986
Rep Power: 41 
Hi!
The warnings are from gnuplot they mean "you've given me a series (t_n,y_n) were all y_n have the same value, I'll extend the yrange to [y_neps,y_+eps]", but something should be plotted anyway (if there are more than two timesteps in the logfile). One problem could be that the watcher waits for a timestep that never comes before plotting. Try playing around with tail to fix that. Could you give me more information about the Logfile you're trying to process? Bernhard
__________________
Note: I don't use "Friend"feature on this forum out of principle. Ah. And by the way: I'm not on Facebook either. So don't be offended if I don't accept your invitation/friend request 

February 4, 2009, 11:10 
Hi ,
I am using lesInterFOA

#22 
Senior Member
Suresh kumar Kannan
Join Date: Mar 2009
Location: Luxembourg, Luxembourg, Luxembourg
Posts: 129
Rep Power: 9 
Hi ,
I am using lesInterFOAM to run my simulations. I want to plot my residuals and check if my solution is converged or not. I found that there are two ways to do that I used the PyFOAMPlotwatcher.py log_file to plot my log file, but it gave me the three plots 1)Residuals vs time steps (unstaedy calculation) 2)continuity vs cummulative and global 3)Bounded variables (K_min,k_max,Kavg) I cannot understand the significance of the first two plots, could somebody explain to me the first two plots in terms of convergence with respect to OpenFOAM I also used the foamlog script to make a directory which has the relevant data. But How do I plot them correctly. since i am a new user any help will be appreciated bye 

February 4, 2009, 12:29 
Hi,
I used the foamLog com

#23 
Senior Member
Suresh kumar Kannan
Join Date: Mar 2009
Location: Luxembourg, Luxembourg, Luxembourg
Posts: 129
Rep Power: 9 
Hi,
I used the foamLog command on my log file and I got the logs directory. The directory contains files pd_0,pd_1,pdIters_0,pdIters_1,pdfinalRes_0,pdFinal Res_1 I used xmgrace to plot these files, but i want to be sure what each of these files correspond to, for eg if i want to see the final residual of my pressure correction equation and pressure equation(pd) over time step which files do I have to plot. bye 

February 5, 2009, 05:46 
I have made a residuals plot u

#24 
Senior Member
Suresh kumar Kannan
Join Date: Mar 2009
Location: Luxembourg, Luxembourg, Luxembourg
Posts: 129
Rep Power: 9 
I have made a residuals plot using the PythonPlotwatcher.py on my log file, but can somebody explain what this script plots from the log file, just a brief explanation is sufficient
if required i can send the plot as well how do i post my graph on this message space. bye with regards K.Suresh kumar 

February 5, 2009, 06:06 
Hello everybody,
I need som

#25 
Senior Member
Suresh kumar Kannan
Join Date: Mar 2009
Location: Luxembourg, Luxembourg, Luxembourg
Posts: 129
Rep Power: 9 
Hello everybody,
I need some help in understanding the log file. I am using lesInterfoam for simulation of liquid being injected in to a chamber under pressure difference Courant Number mean: 0.0031196519 max: 0.4989031 deltaT = 8.5500283e09 Time = 3.770929904e05 MULES: Solving for gamma Liquid phase volume fraction = 0.0015046647 Min(gamma) = 5.2829736e11 Max(gamma) = 1 MULES: Solving for gamma Liquid phase volume fraction = 0.0015048032 Min(gamma) = 1.0746907e11 Max(gamma) = 1 MULES: Solving for gamma Liquid phase volume fraction = 0.0015049417 Min(gamma) = 5.7332803e11 Max(gamma) = 1 smoothSolver: Solving for k, Initial residual = 0.00045105006, Final residual = 8.3348678e08, No Iterations 3 bounding k, min: 1.2895711e09 max: 12308.897 average: 94.35856 smoothSolver: Solving for Ux, Initial residual = 0.01244294, Final residual = 8.2049502e07, No Iterations 3 smoothSolver: Solving for Uy, Initial residual = 0.0026720077, Final residual = 1.3961205e07, No Iterations 3 smoothSolver: Solving for Uz, Initial residual = 0.030640138, Final residual = 6.3619817e08, No Iterations 4 GAMG: Solving for pd, Initial residual = 0.33910157, Final residual = 0.0029885117, No Iterations 12 GAMGPCG: Solving for pd, Initial residual = 0.015574446, Final residual = 6.190298e07, No Iterations 61 time step continuity errors : sum local = 1.0611522e11, global = 2.129606e13, cumulative = 3.2031832e10 ExecutionTime = 64859.16 s ClockTime = 64890 s Courant Number mean: 0.003118677 max: 0.49893967 deltaT = 8.5500283e09 Time = 3.771784907e05 MULES: Solving for gamma Liquid phase volume fraction = 0.0015050802 Min(gamma) = 4.7481924e11 Max(gamma) = 1 MULES: Solving for gamma Liquid phase volume fraction = 0.0015052187 Min(gamma) = 5.7624764e12 Max(gamma) = 1 MULES: Solving for gamma Liquid phase volume fraction = 0.0015053572 Min(gamma) = 1.4955086e11 Max(gamma) = 1 smoothSolver: Solving for k, Initial residual = 0.00044780268, Final residual = 8.0865222e08, No Iterations 3 bounding k, min: 1.5803901e09 max: 12310.74 average: 94.450017 smoothSolver: Solving for Ux, Initial residual = 0.012391458, Final residual = 8.2098518e07, No Iterations 3 smoothSolver: Solving for Uy, Initial residual = 0.0026448201, Final residual = 1.3871489e07, No Iterations 3 smoothSolver: Solving for Uz, Initial residual = 0.030546766, Final residual = 6.7991922e08, No Iterations 4 GAMG: Solving for pd, Initial residual = 0.32492639, Final residual = 0.0031413767, No Iterations 8 GAMGPCG: Solving for pd, Initial residual = 0.014844994, Final residual = 7.1476504e07, No Iterations 61 time step continuity errors : sum local = 1.2763008e11, global = 5.349711e15, cumulative = 3.2031297e10 ExecutionTime = 64881.31 s ClockTime = 64912 s From the details of my log file as posted above i can see that my gamma value is bounded between 4.74881 and 1. the final residual for k shows that k is converging to 8.0e08. which is fine . the Ux, Uy and Uz are also fine. My only concern is about the pd can anybody explain the first line GAMG:solving for pd where the final residual is 0.00314137767, which i think is not satisfying to me. also what does the second line GAMGPCG:solving for pd correspond to where the final residual is 7.14e07. From the time step continuity errors i understand that my continutiy equation is converged to 1.27e11. I have also managed to plot the log file using PyFOAMPlotwatcher.py, but i need some idea about the log file. bye K.Suresh kumar 

April 20, 2009, 05:59 

#26 
Senior Member
Daniel WEI (老魏)
Join Date: Mar 2009
Location: Beijing, China
Posts: 689
Blog Entries: 9
Rep Power: 13 
That's exactly what I need! Thank you Jose, and thank you Bernhard!
__________________
~ Daniel WEI  Boeing Research & Technology  China Beijing, China 

May 13, 2009, 03:58 

#27 
Senior Member
Wolfgang Heydlauff
Join Date: Mar 2009
Location: Germany
Posts: 136
Rep Power: 13 
Plotting Residuals (or forces) on the fly with gnuplot without any further pyFOAM problems see my tutorial under http://www.cfdonline.com/Forums/ope...residuals.html


October 7, 2009, 12:37 
Same Problem

#28 
New Member
Jacques
Join Date: Oct 2009
Posts: 15
Rep Power: 9 
PyFoambin/lib64/python2.6/sitepackages/PyFoam/FoamInformation.py:5: DeprecationWarning: The popen2 module is deprecated. Use the subprocess module.
from popen2 import popen4 Warning: empty x range [1:1], adjusting to [0.99:1.01] Warning: empty y range [0.000908794:0.000908794], adjusting to [0.000899706:0.000917882] Warning: empty y2 range [0.000908794:0.000908794], adjusting to [0.000899706:0.000917882] Warning: empty x range [1:1], adjusting to [0.99:1.01] I'm having the same kind of problem when running pyFoamPlotWatcher I have just installed the svn version of PyFoam and I'm running Foam 1.5. I am also running in OpenSuse : > Linux 2.6.27.230.1default (openSUSE 11.1) > Python 2.6 > gnuplot 4.2 patchlevel 3 > Also the funny thing is when I use the options to write out the residuals in a file , the files are output without a problem and list all the timesteps... Any help appreciated. Last edited by jackpap; October 7, 2009 at 13:07. 

October 9, 2009, 13:22 

#29  
Assistant Moderator
Bernhard Gschaider
Join Date: Mar 2009
Posts: 3,986
Rep Power: 41 
Quote:
Bernhard 

April 25, 2013, 16:57 

#30 
New Member
Rajesh Kumar
Join Date: Apr 2009
Posts: 24
Rep Power: 9 
Hi All.
I am using buoyantPimpleFoam and the residuals of k_0, Ux_0 are fluctuating and does not come down ( I mean below 1e5). I am running on a very fine mesh. What could be the problem. Rajesh 

Thread Tools  
Display Modes  


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Plotting residual in paraFoam  booz  OpenFOAM Paraview & paraFoam  3  August 12, 2008 06:35 
Realtime residual and results plotting  simone Marras  Main CFD Forum  6  January 29, 2007 08:57 
XY plotting  Babu  FLUENT  1  March 25, 2005 06:45 
residual plotting in Prostar  Ossi  CDadapco  15  March 14, 2003 08:54 
plotting the value of yplus  Dennis  CFX  3  May 16, 2002 13:43 