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posteval command
Posted Feb 5, 2010, 8:28 p.m. EST 2 Replies
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Dear all,
I am trying to evaluate a normal diffusion flux of a certain quantity (say variable u) through the internal boundary (say the edge number [5]) in my comsol script (matlab framework, model is in 2D, comsol version is 3.4).
I guest I should use the "posteval" command in the form posteval(fem,'ndflux_u_certainmode',...), but the sintaxis is not clear.
Can someone suggest me what is the way to describe this in the script.
Thank you,
Ismail
I am trying to evaluate a normal diffusion flux of a certain quantity (say variable u) through the internal boundary (say the edge number [5]) in my comsol script (matlab framework, model is in 2D, comsol version is 3.4).
I guest I should use the "posteval" command in the form posteval(fem,'ndflux_u_certainmode',...), but the sintaxis is not clear.
Can someone suggest me what is the way to describe this in the script.
Thank you,
Ismail
2 Replies Last Post Feb 6, 2010, 5:14 a.m. EST
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Posted:
1 decade ago
Hi
Indeed you have "posteval" for evaluation over boundaries, and "postinterp" for interpolation over a line, area etc, and finally "postplot" for plotting, the latter has similar function call variables, for a different output.
These are rather complex functions as you get structures out and you have many options in. I do not use them often enough to learn all that by hart, I tend to stick to the COMSOL GUI, as often I do not have the time to go deep enough into complex matlab prcessing. As an engineer in a development lab my requests for anlysis are always "for yesterday", no time to make nice plots or fancy calculations, unfortunately. Even if I blieve its worth to master these functions well.
So each time I must use these functions, I restart my indexed search on the pdf docs and look for the descriptions and the many examples scattered all around, and I study the "m" files and history files of my models, specially I use the plot file notations to study the call variables.
For the output analysis, start with a simple example, until you get hand on the structure and the order of the elements.
And if you write up a nice cookbook, with further examples, pls post it here, it could help us other too ;)
Good luck
Ivar
Indeed you have "posteval" for evaluation over boundaries, and "postinterp" for interpolation over a line, area etc, and finally "postplot" for plotting, the latter has similar function call variables, for a different output.
These are rather complex functions as you get structures out and you have many options in. I do not use them often enough to learn all that by hart, I tend to stick to the COMSOL GUI, as often I do not have the time to go deep enough into complex matlab prcessing. As an engineer in a development lab my requests for anlysis are always "for yesterday", no time to make nice plots or fancy calculations, unfortunately. Even if I blieve its worth to master these functions well.
So each time I must use these functions, I restart my indexed search on the pdf docs and look for the descriptions and the many examples scattered all around, and I study the "m" files and history files of my models, specially I use the plot file notations to study the call variables.
For the output analysis, start with a simple example, until you get hand on the structure and the order of the elements.
And if you write up a nice cookbook, with further examples, pls post it here, it could help us other too ;)
Good luck
Ivar
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Posted:
1 decade ago
Thank you Ivar,
I just tried the postevai command in the following way:
pd = posteval(fem,'ndflux_u_certainmode','Dl',5,'Edim',1);
It seems it works. After pd is calculated, pd.p field gives the points along the edge [5], and field pd.d gives the required data at these points along the [5].
Best wishes,
Ismail R.
I just tried the postevai command in the following way:
pd = posteval(fem,'ndflux_u_certainmode','Dl',5,'Edim',1);
It seems it works. After pd is calculated, pd.p field gives the points along the edge [5], and field pd.d gives the required data at these points along the [5].
Best wishes,
Ismail R.