I am trying to find a simple way to convert an expression in D notation to the corresponding expression in Diff notation.
In particular I am interested in expressions, such as -D[1](f)(x-y,z-y)-D[2](f)(x-y,z-y), which should become Diff(f(x-y,z-y),y).
Can maple handle this?

I am trying to produce a publication-quality graph. The graph consists of several curves and is a combination (using the *display* command) of some output from *plot* and *odeplot*. I have uploaded the Maple 10 worksheet, plotFig1.mw, that produces the graph so that others can see what I've done. I have also uploaded plotFig1.eps, the encapsulated postscript file that contains the graph exported from the final graphic in this worksheet.
I have tried different possibilities but am still disappointed with the quality of the curves produced, especially the "aliasing" (zigzagging horizontal and vertical line segments that poorly simulate smoothness) near the maxima of these curves.

I would like to plot in 3D a solenoid toric in cylindrical coordinates.
here is the system equation.

Download 4968_Solenoid toric.docView file details
I would like to plot this solenoid toric equation in maple 11
in this file
Please replace this text with the link to your file.
The link can be found in the

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I'm glad to see the dot operator and I'm trying to get around some limitations since it doesn't understand general matrices and vectors. Consider the expression
T(g(a)).h(a).
In my case, T is a transpose operation and a is a vector. I'm trying to differentiate it with respect to a. The general derivative is of the form,
T(h(a)).diff(g(a),a) + T(g(a)).diff(h(a),a).
My question is how to get Maple to understand how to apply this particular derivative rule. If I just blindly apply the derivative, I get the second term fine, but the first term is not in a useful form. Basically, I need to tell diff how to carry out the product rule for these non-commutative terms.

What is the fastest code for integer dot product in Maple ? I am currently using the inner command, however there seems to be a lot of overhead. It is easily slaughtered by GMP. I was wondering if there is a dedicated external routine or something else that I can call ? I want to avoid linking in a C library just for this.
On a related note, I think Maplesoft should develop a companion to the LinearAlgebra:-Modular package that supports fast operations with dense integer matrices in compiled code. I know the LinBox library supports this, maybe it could be linked in ? I actually don't

In the attached file I have a variable RT_FR which appears in the system equation a1.

Download 2129_forMaple(RT_FR).mwsView file details
If I do the following (mb,tr,Ic are parameters)
>RT_FR:=0:
> a1 := -(PSX*sin(s1)*tr-RT_FR+mb*tr*vHn*v1)/(mb*tr^2+Ic);
a1 := -11.64824973 vHn v1
then the numerical procedure - RT_FR is declared global - which is called by odeplot behaves exactly as it should.
However if I do the following

I would like to plot a projection using parametric equations:
x=la*cos(fi)
y=fi
fi=

I assigned d as 10t like this-
d:=10t
How do I "unassign" d? I tried the unassign command and got this:
Error, (in unassign) cannot unassign `10*t' (argument must be assignable)
10 t
How do I get rid of/clear/unassign what I assigned to d?

Hello all,
I know several people around my university that have had this problem so I finally thought I should ask:
Lets say I have some complicated integral, the integrand is a function of several variables. If I:
1)simply evaluate it and I get some function of the remaining variables.
2)try to assign it such as A:=(x,y,z)-> integral, I get A(x,y,z)=integral
what I want is to first evaluate to a function and then assign that function as some name as a function of the remaining variables.
I know this must be possible, but I can't seem to get it.
Thanks for the help.
(I can provid

I am having a lot of trouble converting my LaTeX files to .qu with a wide variety of problems. The first one is a successful conversion but instead of an [OK] I get the message "Error Handling".
LaTeX3.qu: Error handling
In being fed up with the converter, I added questions and converted them one at a time. The problem is with this particular question, text below:

Download 5024_LaTeX3.texView file details
Hello all.
I want to be able to use Maple to do algebra with variables which do not commute with each other. Is there any way I can do this? Really, all I want to be able to do is specify that X*Y - Y*X != 0, and then have Maple recognise that for more complicated functions of X and Y.
I have been looking through the documentation in the help system and have found no clues.
Many thanks in advance for your help.
Dave Abergel

Just a quick question again: if I create a function by way of, say: f := x->2x; then I can't use the plot builder by right-clicking the result. However, defining an expression as f := 2x; works fine. I realize that the plot builder pulls in the function literally and it doesn't like the format of x->2x. However, I'm just finishing up a student manual, and since it is a tad bit confusing, I just wanted to make sure that this is the intended behaviour, and that I'm not missing anything.
Thanks again,
/Ivan

Can Maple produce plots of data with error bars ?

When I post a question, at the top of the screen it says I get one point. What is that for?