Should restart always be in separate execution group? I noticed when I write something like

>restart;
  foo:=proc()
  local sys;
  with(DynamicSystems):
  sys := TransferFunction(25/(s^2+4*s+25)):
  print(ResponsePlot(sys, Step(),duration=4));
end proc;
>

then type foo(); in the next execution group, it does not work. The plot is not generated. No matter how many times I evaluate the execution group. The proc() does not seem to be fully defined. But if I do this:

>restart;  #hit return
>foo:=proc()
  local sys;
  with(DynamicSystems):
  sys := TransferFunction(25/(s^2+4*s+25)):
  print(ResponsePlot(sys, Step(),duration=4));
end proc;
>#hit another return

and now calling foo(); then it works, and the proc() returns the plot. Only difference is that restart was in separate group. But also I had to call foo() once, then evaluate the execution group where foo() is defined two times ! for it to work (why two times?) why one time did not work? is it becuase I am loading package inside the proc()?

What are the rules for putting the restart() call? Should it always be in separate group? I put it in the same group, so that I do not have to hit return 2 times, being a lazy person. But it seems to cause problem sometimes.

And related question, why did I have to hit return 2 times in the execution group to have proc() work in the second case above?

Here is my unsuccessful try

>restart; plots:-contourplot(exp(2*x/(x^2+y^2)), x = -2 .. 2, y = -2 .. 2,
grid = [100, 100], coloring = [blue, red], contours = [.1, .3, .5, 1, 2]);

Hi everybody,

I have some experimental data from an oscillating system (time domaine) and I would like to get an approximation of the damping ratio (zeta). I have already try to use the half-power band width method with the vibrationdata Matlab package designed by Tom Irvine. But I would like to double-check the result with another method.

I found several methods in this paper and I would like to try to do the curve fitting method with the Curve Fitting Toolbox of Maple or Matlab (R2014b) (2.2.2 Curve fitting in the paper). data.txt

It's the first I use this Toolbox with a custom equation, so, I do not really know how to do it with my sample data.

Can anybody help me with this ? I have attached the .txt file sample data to this post.

Cheers

Hi,

I was wondering how to go about plotting a Fourier Tranform in Maple.

My assignment is to plot a simple harmonic equation as a Fourier transform, depicting amplitude against fequency.

I've been given: x'' + w^2 x = 0

And want to obtain both the f(x) = a0 sin(wt) + b0cos(wt) form, and a graph of the the amplitude (c^2 =a0^2 + b0^2) against frequency.

I know how to do this on paper but not in Maple, so any help with line commands and layout would be very much appreciated.

Thanks

PrimesQuestion.mw

Please let me know if this link correctly accesses my worksheet. If not, I will copy its contents into this question.

Which ODE in the worksheet, if any, provides the correct answer?

Hi,

I'm trying to work out whether or not Maple will be able to help me out with some algebra involving lots of indices, but I can't seem to work out how the gauge indices features work in the Physics package. For example I would like to define a gauge field carrying an SU(3) index and a spacetime index. The SU(3) index should run from 1 to 8 and the spacetime index from 1 to 5. I think I have worked out how it works with spacetime indices but I can't seem to find any documentation on the gauge indices.

Is there are a way to set the "dimension" of the gauge index, like we can set the space time dimension?

Cheers

Hi,

  I would need to get access to the values of euler angles defining the orientation of a 3D plot.

I generate the 3D plot with a given orientation, then the user is allowed to rotate it with mouse orbit. How can I get the values of the new euler angles to use them in further computations?

In the plot/structure I cannot find any data concerned with orientation...

Thank you.

Marco

Hi,

I am trying to solve an equation and plot it as an implicit plot, I would like to increase the number of points in the plot calculation but it seems that there is a limit for it, I chose 10^8 and for a bigger values I get an memorry error from Maple. Is there anyway I can solve this problem?

This is just for an example:

implicitplot(subs({values = ...}), function), for a given values, numpoints=10^8)

Regards,

Baharm31

Is there a simple way to see wich packages that I have loaded, without being forced to see thru the entire document?

I have a system of equations in several variables and I just need one numerical solution of it, I tryed to use fsolve of Maple but it always show me some errors or gives back the command as the output.

aaghulu := {-6-4*y-x-(1+y)*x+sqrt((4*(1+y))*(2+x)*(4+2*y+x)+(-(1+y)*x+2+x)^2), (2*(4+2*y+x))*(1+y)-(1+y)*x+2+x+sqrt((4*(1+y))*(2+x)*(4+2*y+x)+(-(1+y)*x+2+x)^2)-(2+y)*(-(1+y)*x+2+x+sqrt((4*(1+y))*(2+x)*(4+2*y+x)+(-(1+y)*x+2+x)^2))};

fsolve(aaghulu, {x, y}, maxsols = 1);

I will be happy if someone guide me how to do these kinds of things using Maple.

Using worksheet, in 2015. I have an execution group, such as

>....code
....
...

>... another execution group

And want to copy all the code from the first group, using the mouse. Is there another way, other than having to move the mouse by hand and select all the code in order to copy it?  In Mathematica, I can right-click on the cell edge, and select copy. This copies the cell to the buffer, then one can paste the code somewhere else. In Maple, I could not duplicate this behaviour which is annoying when one wants to copy large amount of code.

I found that if I put the code in a "code edit region", ie., do insert->code edit region, then right-click inside the small window of the code edit region, the copy is enabled, so I can copy the whole region without manually select it first.

But this does not work outside the code edit region.

This is a stripped down example of something I've been doing. Basically I'm building matrices which I then, using unapply, convert into functions of some variables of t.
.... but found that simplify seems to often not work as i'd wish.
 

restart:
mm:=Matrix([[cos(sqrt(g__1^2)*t), (-I*g__1*sin(sqrt(g__1^2)*t))*(1/sqrt(g__1^2))], [(-I*g__1*sin(sqrt(g__1^2)*t))*(1/sqrt(g__1^2)) ,cos(sqrt(g__1^2)*t)]]);

#great - simplifies as i'd expect:
simplify(mm) assuming g__1::positive;

Do the same thing but when matrix is a function of t
mmFun:=unapply(mm, t);

#the function works - gives what i'd expect
mmFun(3); mmFun(t);

#but now the simplification does not work - why the g__1 in the argument of cos does not get properly simplified?
simplify(mmFun(t)) assuming g__1::positive;

Any ideas if this is a bug? I'm using maple 2015.2 on linux 64-bit.

here is the worksheet: simplify_issue.mw

thanks

EDIT:

as a side note once can sometimes overcome this with mapping simplify  as in :

map(simplify, resultMatrix ) assuming g__1::positive;

but this is not optimal, and sometimes does not work when i first multiply the matrix by say a vector.

Hi all

Assume that we have folowings:

Assume that we devide [0,1] to N subintervals and in each subinterval we have:

Also we want to approximate arbitrary function x(t) with following manner:

How can we produce these basic polynomials?

Thanks in advance

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

Hello,

I would like to create a function from an equation.
I have define 4 functions u[1](t), ..., u[4](t).
From these 4 functions, I would like to define 4 equations. I would like to obtain this result:
Equ[1]:=u[1](t)=L/2*cos(w*t+phi[1])
Equ[2]:=u[2](t)=L/2*cos(w*t+phi[2])
Equ[3]:=u[3](t)=L/2*cos(w*t+phi[3])
Equ[4]:=u[4](t)=L/2*cos(w*t+phi[4])

My code is the following:

for i to 4
do
u[i]:=unapply(L/2*cos(w*t+phi[i]),t);
Equ[i]:='u[i](t)'=u[i](t);
end do;

These lines are not working because the left member is not incremented (u[i](t) stays at each iteration u[i](t))

Generally, how can I transform a function to an equation ?
And, in this specific case, how can I obtain the four equations mentioned above ?

Thanks a lot for your help.

Hello,

I would like to obtain all the solutions of a equation.

Here an extract of my code:

v:=unapply(H*sin(w*t),t);
L:=0.080;
H:=0.020;
Vf:=0.3;
w:=10;
fsolve(v(t)=0,t=0.5..2);

How can I do to obtain all the solutions of the equation in the wanted interval ?

I'm not fixed to use fsolve function.

Thank you for your help