I have a worksheet. I edit some variables' value. I then execute the whole worksheet to see how the graphs change. But the graphs generated by display command do not appear. All other calculations update fine. 

To overcome this. I save worksheet with my new variable values. Close the worksheet. Reopen it. Execute it. And now the graphs appear fine.

Book1.xlsHelow ,

 I want to plot a gaph the data is store in excel sheet. thanks in advance

 I have a complex set of mechanical linkages and components, and I am trying to create a feedback control system for trajectory-tracking with the end-effector. They system is driven by a set of prismatic joints (representing ideal series-elastic actuators). At this stage I am simply trying to establish the control parameters and the required forces to achieve desired positions/velocities in the workspace, and have not yet inserted any realistic actuator characteristics.

An open-loop solution can be found using translational position control on the prismatic joints, this is no problem. However to close the loop properly, I need to convert the system to use a differential input, such as a velocity driver. At this point everything becomes very finicky and highly dependent on initial conditions. Generally Maplesim gives up, claiming that no solution can be found. Due to the complexity of the system, there is no way for me to guess a priori the appropriate initial conditions of all the joints and linkages. I was wondering if anybody had any tips for either pre-determining the initial parameters, or alternatively for relaxing the solver in some way to allow for a wider exploration of possible solutions. Or any other ideas!

So far: I have tried setting up an open loop position-driven system with the same trajectories and using Maple to read all the initial conditions, then transferring them as guesses to my closed-loop system. But this has not worked. As a temporary workaround I am using position drivers on the SEAs, which are in turn driven by a velocity controller (with an integrator term). However this is suboptimal. Any help would be much appreciated!

int((1-r^3+3*r^2-3*r)(r^3-3*r^2+3*r), r = 0 .. 1);
print(`output redirected...`); # input placeholder
/ 3 2
| / 3 2 \ / 3 2 \
int\-r\r - 3 r + 3 r/ + 3 r\r - 3 r + 3 r/

\
/ 3 2 \ |
- 3 r\r - 3 r + 3 r/ + 1, r = 0 .. 1/

I  often find mself in the following quandry: I am investigating a problem, I do a few examples, run a do loop for j from1 to 5 to see if that works and then enter

for j from 1 to 200 do  a[j]:=blah, blah,...  end do:

and 15 minutes later nothing has happened. Is the loop finishing up with j = 198 or so or is it stuck at j = 23 and it will take forever to finish? Or perhaps there is an error that turns up for j > 23?

When I think about it I can insert a print(j) command to keep track of this but there are other situations where that doesn't work. For example,

Order := 35; mtaylor(....

When nothing happens is that because the calculation is almost done? or stuck? etc.

Is it possible to take a quick peek at the state of Maple and the decide whtether to continue the computation or abort? If the calculation of mtaylor(... is particularly long I might settle for the 15 coeficients computed so far rather than abort. Can I get at those?

Any advice?

¿How can I substitute multiple variables with the alsub command at the same time?

For example, if I want to substitute  x=x1, y=x2, .... into the expression f=x*y+x^2+.... using just one command

Hi everyone,

Command "discont" can return the discontinuous point of the function. 

In Maple Help, it says that multiple discontinuities may be expressed with _Zn, _NNn and _Bn but just show the _Zn case and the _NNn case.

Can anyone offer the _Bn case?

Thanks!

Hi everyone,

I have a question about surface fitting. I tried to follow the step of application "Fitting an Ellipse to Data" to fit the ellipsoid surface but got the incorrect result:

It seems that the convergence condition can be modified but I have no idea. 

The related Maple file is attached:

Ellipsoid_Surface_Fitting.mw

I'd appreciate any help on this topic. Thank a lot.

Hi,   I want to substitute every  U[jj+1,-1] by U[jj+1,1] in these lines. Many thanks to send your remarks.
U[jj+1,-1]:=U[jj+1,1];

for jj from 1 to M do:
  sys[jj] := eval(BTCS_general,j=jj);
od;

subs(U[jj,M+2]=U[jj,M]; U[jj+1,-1]=U[jj+1,1], sys);

  Why in this equation U[jj+1,-1] doesnt changed by U[jj+1,1];
                    s u[i + 1, -1]   4 s u[i + 1, 0]   6 s u[i + 1, 1]
      u[i + 1, 1] + -------------- - --------------- + ---------------
                           4                4                 4       
                          h                h                 h        

           4 s u[i + 1, 2]   s u[i + 1, 3]          
         - --------------- + ------------- = u[i, 1]
                  4                4                
                 h                h                 

What is the set of the points (x,y) s. t.

y^2+y^3+(y^3-x^2-3*x*y)^(1/4) <= 5*x*y ?

How to draw it with Maple?

Hello those who attends Mapleprimes,

I have a question.

A programme was written in a text:

n:=5

if n=0 then

0

elif n=1 then

 1/2

elif n=2 then

  sqrt(2)/2

elif n=3 then

  sqrt(3)/2

else error "bad argument: \%1", n;

end if; 

The answer of this programme was 

 error bad argument.

What I couldn't understand was the meaning of \%1

Could you tell me about it to me?

Thanks in advance.

taro

Dear people in mapleprimes,

I have a question which is probably very elementary.

> integers:=[10..15]:
> select(isprime, integers);
Then, "Error, selecting function must return true or false" appears.

On the other hand, 

> integers:=[$10..15]:
> select(isprime, integers);

Then , [11, 13] appears.

What role does the character "$" play here? 

 Thank you in advance.

taro

Using the Fourier convolution theorem to solve f(t) =sin (t)

f(t)=R dJ(t)/dt+J(t)/C

R dJ(t)/dt+J(t)/C=f(t)

where f(t) is a driving electromotive force. Use the fourier transform to analyze this equation as follows.

Find the transfer function G(alpha)  then find g(t) .

 Thanks ....

Hi ;

I need your help to write the system contains all these equation:



# system 1
u[0,0]:=(1/2)*(u[1,0]+u[0,1]);
u[0,N+1]:=(1/2)*(u[0,N]+u[1,N+1]);
u[N+1,N+1]:=(1/2)*(u[N+1,N]+u[N,N+1]);
u[N+1,0]:=(1/2)*(u[N,0]+u[N+1,1]);
# system 2
for j from 1 to N do
u[0, j] := (1/4)*(u[1,j]+u[1,j]+u[0, j-1]+u[0,j+1]-f[0,j]*h^2);
end do;
# System 3
for j from 1 to N do
u[N+1, j] := (1/4)*(u[N, j]+u[N-1,j]+u[N+1, j-1]+u[N+1, j+1]-f[N+1,j]*h^2);
end do;
system4
 eqs := [ seq(seq(Stencil[1](h,i,j,u,f),i=1..N),j=1..N)];

How can collect these system 1 system2, system3 ans system4 in a set with one name.


sys:=[eqs,system3,system2,system2]; ( sys: here contains all the equation).

Thanks you.