Bendesarts

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These are questions asked by Bendesarts

 

I would like to define all the geometry parameters in a multibody model in MapleSim in mm.

Consequently, i define the mm unit for a parameter in 3 places :
1)  in the Parameters area of the subsystem 

2) in the Tab Inspector of the subsystem

 

3) in the Tab Inspector of the rigid body frame of the subsystem

 

The problem is that I receive the warning "Possible double conversion unit on a parameter" and the dimension seems to be as 10^-3 *mm soit too much reduced.

I see that in some examples of the library of Maplesim the parameters of the parameters area of a subsystem are defined as real and consequently, it doesn't cause this kind of problem.

However, how can I do if I want to define my parameters in the parameters area of a subsystem as a position in mm ?

Thanks a lot for your help

 

 

Hello,

I use for the 3D visualization the component CAD geometry with STL files.
My STL files are created from CATIA with parts mesured in mm.
In MapleSim, in order to keep mm, I have, of course, to set "mm" in the inspector tab of the components "CAD geometry".
But, I have also to put the scale factor to 0.001.
I don't understand why I should to set it to 0.001 because :
- the CADs from CATIA are in mm.
- and the option in the inspector tab of the components "CAD geometry" is also in mm.
Would you have some precisions about the scale factor for the "CAD geometry" element ?

Thank you for your help.

Hello,

I would like to assume a matrix to have only real components.

I have seen that the function assume has some features to assume properties for matrix. But, I didn't find the one that I want : "assume a matrix to have only real components".

This assumation should allow me to suppress this kind of choice in my code :

if A::{complexcons, undefined} then
evalf(1/A);
elif A::rtable and ArrayTools:-NumElems(A) = 1 then
Vector([evalf(1/A(1))]);
else
evalf(LinearAlgebra:-MatrixInverse(A));
end if;

Do you have some ideas ?

P.S: The matrix should be also a square matrix. So, the first code line will probably be : assume(a, 'SquareMatrix')

Thanks a lot for your help.

Hello,

From a simulation software, I obtain in a matlab file my differential equations in the following way :

C_p_e = C_state/C_c;
C_p_f = I_state/I_i;
R_p_e = R_r*C_p_f;
I_p_e = (Se_p_e-R_p_e)-C_p_e;

For theses expressions, I would like to do two operations :
1) Transform it into equations
2) Conduct substitutions so as to change the names of the variables with nicer names.

For this objectives, I could do with the following code:

restart;
eq1:=C_p_e = C_state/C_c;
eq2:=C_p_f = I_state/I_i;
eq3:=R_p_e = R_r*C_p_f;
eq4:=I_p_e = (Se_p_e-R_p_e)-C_p_e
allsubs:= proc(XX )
subs(C_p_e=fs(t),C_p_f=v(t),R_p_e=fd(t),I_p_e=fm(t),C_c=1/k,I_i=m,R_r=c,Se_p_e=fe(t),I_state=int(fm(t),t),C_state=int(v(t),t),XX)
end proc:
eq1_a:=allsubs(eq1);
eq2_a:=allsubs(eq2);
eq3_a:=allsubs(eq3);
eq4_a:=allsubs(eq4);

Now, I would like to automatisation the creation of the equations eq1, eq2, eq3, eq4. For the moment, to create these equations, I have done copy/ paste from matlab.

But, I would like to create these equations eq1, eq2, eq3, eq4 with a automative process from my matlab equations. The reason comes from the fact that I would like to make the same work on bigger system which are composed with numerous equations.

How can I create equations labeled eq1, ...eqn from a list of expressions from matlab ?

Thank you for your help

Hello,

I hope that I will manage to explain my question.

I try to recover the structure of my worksheet by working on XMLElements.

Sometimes, I have in the XMLElements that I recover a XMLElements linked to "Font" and {"encoding" -> "UTF-8"} 

Why for one section defined as "text" and "headling1" I can have a change in "Font"? Is there a possibility to detect this changement for line of text.

In other words, how can I recognize a layout "Font" in a line of a worksheet and how can I change a layout "Font" into a layout "TexttField" ?

Thank you for your help.

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