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-   -   import data from CFX-post to MATLAB/EXCEL (http://www.cfd-online.com/Forums/cfx/23856-import-data-cfx-post-matlab-excel.html)

dhaval April 15, 2007 09:42

import data from CFX-post to MATLAB/EXCEL
 
hi, can u give the procedure to import the data from CFX-post to MATLAB/EXCEL to plot the graph & do the calculation.

Sze Hong April 15, 2007 12:47

Re: import data from CFX-post to MATLAB/EXCEL
 
Create a graph on the CFX post, and when you decide what you plotted, there is a button that says EXPORT.

Omer April 17, 2007 10:45

Re: import data from CFX-post to MATLAB/EXCEL
 
1. You can do it the way Sze Hong says, by plotting the chart and then exporting

2. Or once you have created your point/line of interest. Just press file ---> export--- in csv format, and you have it in EXCEL. ( You cannot export transient results this way though, i think)

Then if you want, you can import your values from excel to MATLAB easily.


Dhaval patel April 21, 2007 12:12

what is the procedure to find coefficient of lift
 
what is the procedure to find the coefficient of lift from velocity vs chord length graph? or pressure vs chord length graph?

Darren Leong April 28, 2011 02:48

Hi guys,

I need help on this too. I have transient run in which i would like Matlab to graph the location of a moving body (X,Y,Z), along with the forces and moments acting on it. So far, I've set up the monitor plots in which the data is stored in *.out files for each time step.

The data sitting in front of me on screen, however I haven't the clue to how to graph them out using Matlab, e.g. Collating them into one data file for plotting or reading the values from each .out file as it plots the graph.

Edit: Just to clarify what i mean is through script rather than manually (e.g. using the mouse) in Matlab.

Kartus May 24, 2011 05:26

I use the export function to export the results in a .csv file. You have to set a location from which it exports the results, so it is always recommended to view the results first in a chart and then export them to a .csv file. Make sure you don't add the header, you can unselect it on the second tab of the export screen, otherwise you have to manually set the rows and columns of the data for Matlab to work.

Use csvread in Matlab to load the results in your workspace. You can check 'help csvread' on how to do that.

Cheers!

Darren Leong May 26, 2011 00:39

Thanks, Kartus. I've managed to do as you've suggested

Results_002 = csvread ('Analysis_Results_002.dat',1,0);


It would have been good to have the labels read, would save me time to manually include them in the plot, e.g.

Timestep = Results_001(:,1);
Mesh_Quality = Results_001(:,2);
Sphere1_Force_X = Results_001(:,3);
Sphere1_Force_Y = Results_001(:,4);
Sphere1_Force_Z = Results_001(:,5);
Sphere1_Moment_K = Results_001(:,6);
Sphere1_Moment_M = Results_001(:,7);... and so on

Kartus May 26, 2011 05:01

To my knowledge it is not possible to read anyhting else then values from a csv file using csvread.

I can't help you with the labels, I add all the labels manually in an m-file and load all the results for different cases from that file. It is a copy-paste solution, not very elegant...

amin_gls March 4, 2013 10:29

hello. i have a question about this . when i export to .csv file and opens it with excel . the data are in different rows and just one column .for example x1 and v1 are in first column i want to be x1 in fist and v1 in second column . how can i do it . thanks for help .:(:confused:

Lance March 4, 2013 11:02

This is really not a CFX issue, but here goes...

It would be something like:
Data/From text/<find your file>/Delimited/<next>/Delimiters: comma/<finish>

amin_gls March 5, 2013 03:28

Quote:

Originally Posted by Lance (Post 411367)
This is really not a CFX issue, but here goes...

It would be something like:
Data/From text/<find your file>/Delimited/<next>/Delimiters: comma/<finish>


thank you .. i did it .

Thomasbr September 13, 2016 08:16

Hello,

I know this thread is very old, but I might have the same issue: I have several defined points P_i (like 100 or so), several reference temperatures (one for each point). For each point, a heat transfer coefficient is computed using the formula:

h(P_i)=\frac{Wall\ Heat\ Flux\ (P_i)}{\text{Reference Temperature}\ (P_i)-300[K]}


What interests me is the weighted average of these HTC's (therefore I cannot use the "monitor point method"):

h_\text{total}=\frac{\sum_iA_ih(P_i)}{\sum_iA_i}

This value only depends on time:

h_\text{total}=h_\text{total}(t)

I want to export the datas ( \text{time step} , h_\text{total} (\text{time step})) to MATLAB. For this purpose, I need the .csv file. Thing is, as far as I know, we can do that with the "export" command in CFX Post only for a given time step.

But I have the chart h_\text{total}=h_\text{total}(t) plotted. Is there a way to get the .csv file direct from the chart?

Or do I have no other choice but to write some script to loop over the time steps to retrieve for each one of them the value of h_\text{total}(\text{time step})?

Thomasbr September 15, 2016 08:32

I finally managed to do what I wanted to, that is, to get a .csv file with the time (in my case variable name = TimeVar) and the value of h_\text{tot} (in my case variable name = AAlphaGesVar) for each time. This might interest someone, so I describe what I did (I learnt a bit of Perl too):

data.csv looks like this:

Code:

9.89989028e-004, 5.02314758e+000
1.02000998e-003, 5.10743713e+000
1.05003000e-003, 5.00016737e+000
1.07995002e-003, 4.82792759e+000
1.10997004e-003, 4.82947874e+000
...

To get this .csv file I wrote this .cse file:

Code:

COMMAND FILE:
CFX Post Version = 16.0
#Enter your version of CFX Post here
END

!use strict;
!use warnings;

!open (OUTFILE, ">", "data.csv");


!for (my $i=34; $i<=169; $i++)
!{
# Start for loop to load different time step
# One need to modify it based on his/her need

!my $resstp=$i;
DATA READER:DATA READER
Current Timestep = $resstp
END
> load

EXPORT:
# export data to test1.csv
ANSYS Export Data = Element Heat Flux
ANSYS Reference Temperature = 0.0 [K]
ANSYS Specify Reference Temperature = Off
ANSYS Supplemental HTC = 0.0 [W m^-2 K^-1]
BC Profile Type = Inlet Velocity
Export Connectivity = Off
Export Coord Frame = Global
Export File = test1.csv
Export Geometry = Off
Export Node Numbers = Off
Export Null Data = Off
Export Type = Generic
Export Units System = Current
Export Variable Type = Current
Include File Information = Off
Include Header = Off
# One can turn header off if it is wanted
Location List = P22
#The value of my variables does not depend on the location, so I put any point here, just modify it based on your need
Null Token = 0
Overwrite = On
# One should turn the Overwrite On
Precision = 8
Separator = ", "
Spatial Variables = X,Y,Z
Variable List = TimeVar, AAlphaGesVar
Vector Brackets = ()
Vector Display = Scalar
END
>export

!open (INFILE, "<", "test1.csv");
!print OUTFILE <INFILE>;
# copy data in test1.csv to output file, which is data.csv
!close INFILE;
!}
!close OUTFILE;

adapted from the script http://www.eureka.im/3771.html


Under CFX Post I clicked on "Session" then on "Play Session" and selected the .cse file. After a couple minutes the file data.csv was written.


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