iMechanica - How to write the transfer function of mechanic systems in C language? - Comments

Re: Matlab .m file to C code

Biswajit Banerjee — Wed, 07 May 2008 17:46:58 -0400

Xianfeng,

There are several ways to pass parameters in an out of C functions. C passes arguments by value. You can see what that means by running Joe Zachary's bit of code at

http://www.cs.utah.edu/~hamlet/release/lessons/c13/examples/value/value.c#valuec

Also look at

http://www.cs.utah.edu/~hamlet/release/lessons/c13/c13/body-node2.shtml

and the main pages at

http://www.cs.utah.edu/~hamlet/ and http://www.cs.utah.edu/~hamlet/release/classes/C/contents.shtml.

To pass a set of parameters into a function you can create a struct. To get a set of modified parameters out you can send in a pointer to a struct . I prefer that approach because of the problematic memory management issues involved in creating structures inside a function and returning them.

I'm not certain how Matlab deals with that issue.

-- Biswajit

Matlab .m file to C code

Xianfeng Ye — Wed, 07 May 2008 04:27:56 -0400

hi Biswajit,

Thank you very much for your suggestions. I also prefer your choice, but I have no idea about that now, so I am going to try mcc first. Thanks again!

Another question is:

If I want to give one input parameter to this C code Model, do I get one output with asssumption that there are one input parameter and one output parameter in the model, while not one series of input parameters and one series of output parameters?

(I don't know why I can't post the comment, I tried several times :)

--Xianfeng Ye

Welcome back, Biswajit!

Zhigang Suo — Tue, 06 May 2008 07:28:18 -0400

Dear Biswajit: So delighted to hear from you again! Hope all is well with you. You must be delighted to see the post by Andy Norris yesterday, inspired by the jClub theme led by you. We miss you and your thoughtful posts.

Welcome back

Temesgen Markos — Tue, 06 May 2008 07:14:15 -0400

Hi Biswajit,

Welcome back, you have been missed in this forum!

Matlab to C

Biswajit Banerjee — Tue, 06 May 2008 02:28:54 -0400

If you are happy with crappy looking code then I would suggest trying

mcc -c myfile

You can find more information at

http://www.kluid.com/mlib/viewtopic.php?t=115

My personal perefernece has been to write a new c version based on the Matlab version.

-- Biswajit

How to write the transfer function of mechanic systems in C language?

Xianfeng Ye — Mon, 05 May 2008 22:08:07 -0400

I have finished building the transfer function model of mechanic systems in MATLAB. But now if I am going to write the model in C language, what could I do? Any hints, fire are welcome!