Hi Again

Assume that we have known matrix namely, Q, of order (m+1)*(m+1) and we want to construct following matrix

where 0(bar) is zero matrix of orde (m+1)*(m+1) and New matrix should be of order {N*(m+1)}*{N*(m+1)} where N is known constant.

thanks for any guide

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

I wrote down a proceduer in maple for solving integro diff. equations which result in an ill conditioned linear system of algebraic equations. I used the LinearSolve command with method=LU to solve the system but my algorithm failed, and does not converge. Is there any command in maple for solving such systems

I tried to get the limit for this sqrt(-2*cos(alpha)*cos(alpha+d)+2-2*sin(alpha+d)*sin(alpha))/d, from right side

input

limit(sqrt(-2*cos(alpha)*cos(alpha+d)+2-2*sin(alpha+d)*sin(alpha))/d, d = 0, right);

return

sqrt(-signum(-2+2*cos(alpha)^2+2*sin(alpha)^2))*infinity;

when tried for next time

limit(combine(sqrt(-2*cos(alpha)*cos(alpha+d)+2-2*sin(alpha+d)*sin(alpha))/d), d = 0, right);

return

1

note that the expression evaluated is the same, but returns different answers, is there somebody know why or how to avoid maple to return wrong answers

Hello,

I have a little question about the display of the kinematic joints which are usually in red.

I didn't know why the kinematic joints have disappeared and I don't know how to display them again.

Do you have an idea about the button I have to use so as to display the kinematic joints.

Thanks for your help.

Hi,

This maybe a really simple question, I remember this is doable but couldnt find where the answer is.

Say I write a function to sum up all values in the list,

mysum:=proc(data::list)

return printf("The sum is %3.3f. ", sum(data[i],i=1..numelems(data)));

end proc;

and I use it like,

mysum(listA);

mysum(listB);

How would I print out a more informative string, like this:

"The sum of listA is %3.3f. "

"The sum of listB is %3.3f. "

Use "data", the input, as a string argument.

Thanks,

casper

Hi all.

Assume that a Matrix P is (m+1)*(m+1) known matrix and we want to construct following special matrix

where

and

how can we do it by maple?

Note that the required matrix is of order k(m+1)*K(m+1)

thanks for any guide

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

Hello,

I would like to modify the chirp signal source. In fact, I would like to put a function for the amplitude parameter instead of a constant.

I would like to obtain this kind of curve that is to say to increase progressively the amplitude.

Do you have some ideas how I can implement a function defined with several parts to define the amplitude parameter of the chirp signal ?

Thanks a lot for your help.

with(plots):

a:=polarplot(3-3*cos(theta),theta=0..2*Pi):

c:=plot((3*sqrt(2)+3)/2 + ((-3*sqrt(2))/(-3*sqrt(2)-6))*(x+((3*sqrt(2)+3)/2)),x=-10..10):

display(a,c,view=[-10..10,-10..10]);

a:= is the polar plot of the cardiod (3-3cos(theta)

In order to plot the tangent line to the cardiod in theta= 3Pi/4, I find the point (x,y) in rectangular coord x=(3-3cos(theta)cos(theta) and y=(3-3cos(theta)sin(theta); then I find the derivative of dx/dy=

[(3-3*cos(theta)*cos(theta)+sin(theta)(3sin(theta)]/[-(3-3cos(theta)sin(theta)+cos(theta)(3sin(theta)]and from here I get the slope.So I can plot c:= tangent line to the cardiod in 3Pi/4.

How can I avoid having to convert everyting to rectangular coords, and plot the tangent line in polars?

I was calculating average BER for BPSK and while its execution encountered kernel failure with an error message as "execution stopped:stack limit reached.worksheet lost connection to kernel.you should save worksheet and restart maple."

how to overcome this error. Any help?

I was browsing this Maple book, and read this below.  This contradicts everything I expected about direct assignment to an element of a list, which I view as an array and should have O(1) cost to modify any one element in it.

So, clearly there is something I don't understand about Maple here or I am not reading this correctly.  Here is the bit from the book I scanned. This is from Computing with Maple, by Wright, page 61, ISBN 1584882360

So is one really supposed to write  

subsop(index=value,L) 

instead of the more normal and natural

L[index]=value

For making changes to list L?

I also do not understand the book when it says "only allowed on small lists anyway". Allowed by whom? Will one get an error if they assign to an index on large List?

I am confused by all of this, and that is why I am asking for clarification.

How do I get the vertical bar "divides" symbol in Maple 18?

Dear Maple experts,

I would like to visualize the equation -3*x+2*y+3*z=0  and (with other color) 2*y+3*z =0. I used the following commands:

with(Student[LinearAlgebra]):
infolevel[Student[LinearAlgebra]]:=1:
PlanePlot(-3*x+ 2*y + 3*z = 0, [x,y,z], normaloptions=[shape=harpoon], showbasis);

But I do not know how to show at the same time the second equation (2*y+3*z=0 ).

How should I proceed? Any hint?

Thanks for your attention,

Jean-Jaques

I am trying to find a way to take the rows of a matrix and put them in a sequence.  For example if i have the matrix 

M:=Matrix(3,[[1,1,1],[2,2,2],[3,3,3]]);

I want to rewrite it as S:= {111222333}.  

Sorry if this is not clear.  I know how to create a sequence, but I want to be able to use the Matrix and output a sequence without manually inputing the numbers.  

Thank you in advance for your help.  

I am finding it a struggle to do this trivial task in Maple.

Given a matrix, I simply wanted to find the positions (index i,j) of all elements that meets some condition. For example, given matrix A:=[[1,2,3,],[4,5,-1]]; I want to find the index of all elements >=3, so the result should be a list of set such as

         [[1,3],[2,1],[2,2]] 

I tried to use member with 'pos' option but that does not work for matirx. It seems only designed for 1D

A:=Matrix( [ [1,2,3],[4,5,-1]] );
c:=select[flatten](x->x>=3,A);  #tried without flatten also
member(c,A,'pos');
pos;

Then I tried rtable_scanblock(), which is the most convoluted and badly documented command I have ever seen in my life (for such a complex command, one will expect 100 examples of many sorts of functionality to illustrate how to use, but only 3-4 trivial examples exist and 3 of them pretty much the same).  What is operation_passindex? what is operation_passnoindex? how to use them? Why is there a star next to val* and operation* ? What is passindex actually? is it a name? value? proc?  etc.. Worst help page ever. 11 parameters for a command??

This is what I tried:

A:=Matrix( [ [1,2,3],[4,5,-1]] ):
rtable_scanblock(A,[],(val,ind,res)->( evalb(val>=3),[ind,val],res),[[1,1],A[1,1]]);

So the result I want is there. I just do not understand why the true,false and those last entries are there and how to get rid of them. I tried. I think I need one other options, but I am lost with all the options listed there with no examples on how to use them.

rtable_scanblock(A,[],(val,ind,res)->`if`( val>=3,[ind,val],res),[[1,1],A[1,1]]);

but then I get only the last value:

I tried

rtable_scanblock(A,[],(val,ind,res)->`if`( evalb(val>=3),[ind,val],res),[[1,1],A[1,1]]);

no difference.  I think I am close, but after 30 minutes, I am calling it quit. If something so easy takes that much effort to find how to in Maple, then something is wrong.

In Matlab, I do this with my eyes closed:

A=[1,2,3;4,5,-1];
[I,J]=find(A>=3)

I =
     2
     2
     1
J =
     1
     2
     3

In Mathematica, such as trivial

mat = {{1, 2, 3}, {4, 5, -1}};
Position[mat, x_ /; x >= 3]

                 {{1, 3}, {2, 1}, {2, 2}}

Thank you

Hello,

I have a question concerning the initial conditions.

One interest of MapleSim is to enable to model a multibody systems with different kinds of coordinates : namely relative and absolute coordinates.

For a complex system, it seems to me that the determination of the initial position is not an easy task.

Consequently, I wonder if it is possible to determine the initial positions for the system in absolute coordinates thanks to the knowledge of the initials positions in relative coordinates.

In other words, I have already determined the initial positions of my system in relative coordinates but as I would like to simulate my system with absolute coordinates. I wonder if I can have a process to deduct the initial positions for the absolute coordinates for the initial positions in relative coordinates.

Thanks a lot for your ideas and help.