Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

Hi there!

I want to have a procedure, which takes as one of it's arguments an algebraic, say sin(x) for instance. So far thats easy, I just type:

proc(arg)

Within this proc I would like to define a function now, which has this expression on it's image side. So it should look like f:=x->sin(x). What I tried is:

 

minexample := proc(arg)

  local f:

  f := x -> arg:

  f(pi)

  end proc:

minexample(sin(x));

 

But this code would produce sin(x), as a result and not 0, as I would expect. Could anyone tell me what I do wrong, and how I can get it right please? : )

What I would also like to know is, what kind of data type expressions such as sin(x), or algebraic expressions are, so I can specify that in the definition already to make the proc more transparent to use.

 

Thanks!

Please write a Maple procedure called Position which retures the position i of an element x in a list L

That is, Position should return an integer i>0 such that L[i]=x. If x is not in list L,0 is returned..

 

i found command i may need to use 

proc(), do end do ,member(e, a,'p'), if then elif, end proc, 

 

can anyone help with this?  it may be a too elementary question to ask here .....and i know

 beginner 

I tried to get the maximum and minimum values of the following function. From the plot I get them but its not accurate. Please advise me to get them accurate.

 

F:=0.85:B:=0.5:

K:=N->(N*(1+F*N/(N^2+B^2-F*N)));

 

implicitplot(((N^2+B^2-F*N)*K=N*(N^2+B^2-F*N+F*N),K=0..10,N=0..10,view=[0..5,0..4],numpoints=90000,axes=boxed,thickness=2,color=black,font=[1,1,20],tickmarks=[3, 3],linestyle=1));

 

diff(sin(x)^2,x$n); # Maple fails

# then I tried:

combine(sin(x)^2);diff(%,x$n);

# this works, but Maple should drop the pochhammer term (derivation of a constant)

 

What is the reasoning behind the output?

Good afternoon sir.

 

I request your kind suggestion to the above cited question.

 

 

With thanks & Regards

 

M.Anand

Assistant Professor in Mathematics

SR International Institute of Technology,

Hyderabad, Andhra Pradesh, INDIA.

Hello, Suppose I have two sinusoids with the same amplitude and frequency. By changing the phase of one of them it is possible to 'align' them. When the phases are exactly the same the difference between the two sinusoids becomes zero. Now lets define a variable (U[int]) that gives a measure of the difference between the two sinusoids and change the phase phi to generate an animation and 3D plot and see if it is possible to mathematically determine that the difference becomes zero when the phases of the waveforms are equal. Chosing a time t>0 and solving for the derivative does the job.

My question is, can (and how can) Maple determine for which phase phi we have the minimum function without chosing a time t.
 

restart

with(plots):

u[G] := sin(omega*t)

u[L] := sin(omega*t+phi)

U[int] := int((u[G]-u[L])^2, t)+C

C := solve(subs(t = 0, U[int]) = 0, C)

omega := 9:

animate(plot, [[u[G], u[L], (1/10)*U[int]], t = 0 .. 2, legend = ["Public grid voltage", "Local grid voltage (control goal)", "Cum. Actuator voltage (scaled)"]], phi = -Pi .. Pi, gridlines = true, labels = ["Time [s]","Voltage [V]"], labeldirections = ["horizontal", "vertical"], labelfont = ["ARIAL", "bold", 12])

plot3d(U[int], t = 0 .. 2, phi = -Pi .. Pi, shading = zhue, orientation = [-150, 70, 15])

t := 1:

phi = fsolve(diff(U[int], phi))


Download 20131114_Finding_min.mw

 

Thanks a lot!

Hi there,

i want to generate some plots in files in this example:


this code doesn't work. but without restart; it works fine. i passed 2 days to figure out that "restart;" was the problem.

my questions are :

1. why i have to eliminate the first line of restart;

2. how can i save my files in a directory that is in the current directory. For example i have a directory in current directory named "plotFILES".

thanks in advance for your help

Hey, I have some data points:

 

I than entered:

X := Data[() .. (), 1];
Y := Data[() .. (), 2];
f := a+b*x^c+d*x^e;
Statistics:-NonlinearFit(f, X, Y, x);
 and when I entered Statistics:-NonlinearFit(f, X, Y, x);, It wouldn't output anything.

I am using maple 17 and I was trying to run a nested loop as shown below. I expected to get all combinations of i and j (9 components). But i and j always remain 3. What is the problem here? Can anyone suggest alternate solutions? I dont understand in which order maple increments i,j or k in each loop.

 

for k to 9 do

      for i to 3 do

          for j to 3 do

          a[k] := i, j

          end do

      end do

end do;

 

table([1=(3,3),2=(3,3),3=(3,3),4=(3,3),5=(3,3),6=(3,3),7=(3,3),9=(3,3),9=(3,3)

 

Thanks in advance

Greetings,

I have a differential equation:

an the solution:

I want to substitute

ekf := omega = sqrt(c/m);


algsubs(ekf, sol);
but sol does not change.

This works a bit but does not substitute everything in a way that you would expedect

This is the result:





Thanks in advance

I want to find the sum of the reciprocals of the factorials of the elements of in the sets [[0,2,3,0,0], [2,3,0,0,0], [1,1,2,2,0] .....]]  -----(1)

For example 1/(0!2!3!0!0!) + 1/(2!3!0!0!)+ 1/(1!1!2!2!0!)+........;----(2)

The lists are the partion(5) made into a list of 5 elements with 0s filling the partitions with less than 5 elemenst such as (2,2,1)=>(2,2,1,0,0)

All I need is help on how to make from (1) the sum (2) which is the sum of the reciprocals of the products of the factorials of each set. 

Hello,

I would like to choose the maximum interval which is here B3 not the maximum value.I used max which gave me the maximum value. Any ideas?

This is the output:

B1:=[2., 36.718220544331125]
B2:=[2., 35.08378362904457]
B3:=[2., 51.78712780854305]
datamax:= 51.78712780854305

how to get datamax:= [2., 51.78712780854305] instead of datamax:= 51.78712780854305?

This is my Maple code:

> restart;
> n := 3;
> for i to n do A[i] := RandomTools:-Generate(distribution(Uniform(.5, .75))) end do;
> eq := diff(X(t), t) = -S*X(t);
> ic[1] := X(0) = 150;
> for i to n do s[i] := dsolve({ic[1], subs(S = A[i], eq)}, X(t), range = 0 .. 10, numeric) end do;
> for i to n do B[i] := eval([t, X(t)], s[i](2)) end do;

datamax := max([seq(B[i], i = 1 .. n)]);

 

Thank you

Hello,

I am solving eq1 and then plot it using odeplot. Then I am extracting data from odeplot using op[1,1]. From that I only care about  one point so I am using pt[1] := dt[1]([1, 2]); then I ploted it using pointplot. I run a do loop and at the end I am ploting all the points.

My code works fine but I am trying to have a line contacting each points. I tried  style=line but it did not work.

How can I have a line contacting each points on my final plot (which is display([pl[1], seq(allpl[k], k = 1 .. 3)])) ?

This is my code:

> restart; with(DEtools); with(plots);
> with(DEtools); with(plots);
> A := 0.2e-1; B := 10^(-5); k := 0;
> eq1 := diff(X(t), t) = -(A+B*X(t))*X(t);

> ic[1] := X(365*k) = 1000;
> s[1] := dsolve({eq1, ic[1]}, X(t), range = 0 .. .365, numeric);
> p[1] := odeplot(s[1], [[t, X(t)]], t = 0 .. .365);
> dt[1] := op([1, 1], p[1]);
> pt[1] := dt[1]([1, 2]);
> pl[1] := pointplot(pt[1], axes = boxed);
> for k to 3 do
tk := 365*k;
A := rhs(s[k](tk)[2]);
ic[k+1] := X(tk) = 500.*A;
s[k+1] := dsolve({eq1, ic[k+1]}, X(t), range = tk .. 2*tk, numeric);
p[k+1] := odeplot(s[k+1], [[t, X(t)]], t = tk .. 2*tk);
dt[k+1] := op([1, 1], p[k+1]);
pt[k+1] := dt[k+1]([1, 2]);
pl[k+1] := pointplot(pt[k+1], axes = boxed);
allpl[k] := display([pl[k+1]])
end do;
> display([pl[1], seq(allpl[k], k = 1 .. 3)]);

 

Thank you

I am trying to use Maple to produce an image that will be part of a math paper.  The final image must be in .eps format.  Whenever I produce a plot in Maple17 and click on it, it looks like the image has the shape of a square (regardless of what's inside it), perhaps with a lot of empty space.  I want an image without a lot of empty space, and I'd like Maple to do this.  If I crop a square image using some other application, it is not going to improve the quality of the image and might hurt it.  

If the answer to question in the Title is "no", can anyone suggest a good way to produce a good .eps image from a Maple plot that is cropped properly to eliminate as much empty space as possible?  I have Photoshop, but I don't know if this is the best way to go.

I wrote a toy file that plots a simple curve.  I'll upload it and provide a link to it.  If you execute the code and click on the image, you'll see that it is a square with a lot of empty space.

Nov122013.mw


restart:

with(plots):

p1:=plot(x^2,x=0..1,scaling=constrained,view=[-4..5,-1..3]):

display(p1);

 

 

 

 

 


Download Nov122013.mw

 

Can any workarounds in Maple for debugging the code without procedure? 

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