## Who invented the inverse model approach?...

Inverse kinematics can be done in several ways (this webinar gives a very good overview https://www.youtube.com/watch?v=X0OZ9EM6dns). A effective and simple method is to run a model in reverse direction. This can’t be done with causal modeling tools, where information flow is fixed by design (https://de.maplesoft.com/support/help/MapleSim/view.aspx?path=MapleSimUserGuide/Chapter01).

Inverse kinematics, which is possible with acausal modeling tools, is only an example for running a model in the reverse (i.e., inverted) direction.

Without success, I tried to find a reference who first came up with that elegant approach.

Anyone knows more?

## Better printing...

I'd like to print a high res and quality worksheet but maple has very poor printing.

I'd like to change the font so I can print more text. I'd like to change the dpi of the print to get higher quality.

Right now I'm having to print screen then scale in photoshop just to get a halfway decent print. I don't want pages of wrapped text that is very confusing to view. If I zoom out all the way on the worksheet I can almost get what I want as far as the size and wrapping(I want to avoid wrapping and there seems to be no way to turn this "feature" off). Of course when I zoom out and use print screen the quality is extremely low due to resolution issues. [So "zooming out" let's me stuff most of the data in to view that I want but then when I use print screen to capture it the quality is so low as not to be useable due to the dpi issue. Of course if I use any of maples printing "features" it will ignore the zoom scaling so as to be useless]

The only thing I can see on how to solve this issue is to save to latex and modify the latex. The problem is that maple puts a lot of junk formatting in the latex to make the wrapping look the same which is exactly what I do not want.

Maple has a "copy as image" but this doesn't seem to do anything. The printing of Maple really needs to be worked on. It's so limited to be almost useless.

## PDEtools declare but still using the standard part...

I want to know if it is possible to use the declare command from the PDETools package for a function

f(x,y,z)

and still, having the notation $\frac{\partial f}{\partial x}$ instead of $f_x$ for the Maple command %diff(f(x,y,z),x)

Thanks !

Kevin

## error, null fix?...

Hi

Keep getting "Error, null" on every calculation i make. It indicates hidden spaces or something weird????.

Screenshot of it is included.

https://imgur.com/a/wSdUeqe

Would be great with a fix or some help because this is driving me mad....

## Code Editor / file information...

It would be nice to have the file name in addition to the name of the code attachment on the top.

## Smiles file and its graph structure ...

Is their anyway we can get the smiles file of given IUPAC name

Smiles with explicit hydrogen

And draw its chemical graph

## How to remove the mosaic of vertices?...

I  generated some graphs via maple and would like to put them in my paper. So I am going to convert the following worksheet to pdf.

with(GraphTheory):
Graphs:=[NonIsomorphicGraphs(6,8,output=graphs,outputform = graph)]:
num_g:=nops(Graphs):
num:=ceil((num_g)/5.):
M1:=Matrix (num,5,(i,j)->if((i-1)*5+j<=num_g, DrawGraph(Graphs[(i-1)*5+j],size=[250,250] ,overrideoptions ,showlabels=false,style=planar, stylesheet =  [
vertexcolor     = orange
,vertexfontcolor = black
,vertexborder    = false
,edgethickness   = 0.6
,edgecolor       = MidnightBlue
,vertexshape     =  "circle"
,vertexfont      = [Arial, 4],
vertexthickness=5], caption = cat(H__,5*(i-1)+j),captionfont=["ROMAN",7]),plot(x = 0 .. 1, axes = none))):
DocumentTools:-Tabulate (M1[1..5,.. ],widthmode=percentage ,width=80 , exterior =all) :


But there was a problem with the exported pdf. There was some mosaic stuff at the vertices of all those graphs. It was strange. (I want to reduce the size of vertices of the graphs in order not to look crowded.)

Only when I insert the option vertexpadding and set a large enough size  of vertex (for this example, we set vertexpadding=7),  it won't go wrong. However, in fact, we often need make vertice‘s size smaller , especially when there are more vertices.

## How to integrate the given function...

How to integrate the below function from 0 to eta.

A := P(eta)+S(H-2*cos&theta;(eta+1)*F)+cos&theta;*(2*F(eta)-2*H*F) = S(eta+1)*sin&theta;*F(theta)-sin&theta;(F*H(theta)-H*F(theta)+F(theta, eta))

## Contour Plot from list...

Please, how do plot the contour plot of im(qq) vs Re(qq) from the list below:

qq= [2.106333379+.6286420119*I, 2.106333379-.6286420119*I, 4.654463885, 7.843624703, 10.99193295, 14.13546782, 17.27782732, 20.41978346, 23.56157073, 26.70327712, 29.84494078, 32.98658013, 36.12820481, 39.26982019, 42.41142944, 45.55303453, 48.69463669, 51.83623675, 54.97783528, 58.11943264, 61.26102914]

## how to give variable a type and also make it stat...

I need to make my base class local variable static, so that when extending the class, the subclass will share these variable and use their current values as set by the base class. If I do not make them static, then the base class when extended, will get fresh instance of these variable, losing their original values, which is not what I want.

To do this, one must make the base class variables static

This works, but now I do not know the syntax where to put the type on the variable.

I can't write   local m::integer::static; nor local m::static::integer;

I could only write local m::static; but this means I lost the ability to have a type on the variable and lost some of the type checking which is nice to have in Maple. From Maple help:

Here is example

restart;

base_class:=module()
option object;
local n::static;  #I want this type to ::integer also. But do not know how

export set_n::static:=proc(_self,n::integer,$) _self:-n := n; end proc; export process::static:=proc(_self,$)
local o;
o:=Object(sub_class);
o:-process();
end proc;
end module;

sub_class:=module()
option object(base_class);
process:=proc(_self,\$)
print("in sub class. _self:-n = ",_self:-n);
end proc;
end module;

o:=Object(base_class);
o:-set_n(10);
o:-process()

"in sub class. _self:-n = ", 10

The above is all working OK. I just would like to make n in the base class of type ::integer as well as ::static

Is there a syntax for doing this?

## Modeling - EMC Designer...

Hi,

One of my areas of expertise is in Designer Filters EMC. Could any professional that already uses MapleFlow for EMC and Electromagnetism, help me about the main functions of this amazing software?

Thanks.

Leandro Zamaro

## How to make Exported equations readable in excel?...

I have a set of formulas I saved in a matrix and the exported the matrix to Excel. However when I open the file in Excel the equations are in prefix notation (I think).  That's not exactly human readable friendly.  If I copy and paste straight into excel they are readable.

It there a way to make the Maple export similar?

EDIT:-  I exported as a.csv file because if export as .xlsx    all the equation change into "#NUM!" in the spreadsheed.

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## Color Error in plot ...

Hi.

What wrong could be there with the color line?

 > restart:
 > with(plots):
 > equ1 := BesselJ(sqrt(17)/2, 10*sqrt(t)*sqrt(2))/t^(1/4) + BesselY(sqrt(17)/2, 10*sqrt(t)*sqrt(2))/t^(1/4):
 > equ2 := BesselJ(sqrt(17)/2, 10*sqrt(t)*sqrt(2))/t^(1/4) + 5*BesselY(sqrt(17)/2, 10*sqrt(t)*sqrt(2))/t^(1/4):
 > equ3 := BesselJ(sqrt(17)/2, 10*sqrt(t))/t^(1/4) + 5*BesselY(sqrt(17)/2, 10*sqrt(t))/t^(1/4):
 > tmax   := 30: colors := ["Red", "Violet", "Blue"]: p1 := plot([equ1, equ2, equ3], t = 0 .. tmax, labels = [t, T[2](t)], tickmarks = [0, 0], labelfont = [TIMES, ITALIC, 12], axes = boxed, color = colors): ymin := min(op~(1, op~(2, op~(2, [plottools:-getdata(p1)])))): ymax := max(op~(2, op~(2, op~(2, [plottools:-getdata(p1)])))): dy   := 2*ymax:
 > legend1 := typeset(C[3] = 1,  , , C[4] = 1,  , , Omega^2 = 50): legend2 := typeset(C[3] = 1,  , , C[4] = 5,  , , Omega^2 = 50): legend3 := typeset(C[3] = 1,  , , C[4] = 5,  , , Omega^2 = 25): p2 := seq(textplot([tmax-2, ymax-k*dy/20, legend||k], align=left), k=1..3):
 > p3 := seq(plot([[tmax-2, ymax-k*dy/20], [tmax-1, ymax-k*dy/20]], color=colors[k]), k=1..3): display(p1, p2, p3, view=[default, -ymax..ymax], size=[800, 500])
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 >

## How to speed up the calculation of the double inte...

I want to calculate the double integral of the following expression which includes sum of several Legendre polynomial terms, but the speed is so low. Any suggestion to speed up the calculation?

 >
 >
 >
 >
 >
 >
 >
 >
 >

CompositionSeries(SmallGroup(336, 209))
It's mean this function just work in transitive group? But IsTransitive(SmallGroup(336, 209)) will get true. Is it a bug of maple? Or do I have any misunderstandings?