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Hello to you all,

I have this DE

but when I try to change the variable

I get this

>algsubs(r(t) = 1/u(t), diff(diff(r(t), t), t)-k/r(t) = -K/r(t)^2);

Why is it not done for the rest of the terms.  Is there a more easy way to do it.  Take into account that I cannot use dsolve because it is in an course in integral.


Thank in advance for your help.


Mario Lemelin
Maple 2015 Ubuntu 14.04 - 64 bits
Maple 2015 Win 10 Pro - 64 bits messagerie : téléphone :  (819) 376-0987

Does anyone know an easy way to convert %d_ to D? I tried the convert command, but no effect.  Thanks.




For my lecture advanced dynamics, I got the question to make a sketch of the coordinate system and the particle’s motion, with the following position vector:

r(t) = (a cos(ωt))i + (b sin(ωt))j + (ct)k

In this function, ω is in [rad/s], a and b are in [m], t in [s] and c is [m/s].

I have no idea what this should look like, and I was thinking about plotting this with Maple, but thus far I'm not succeeding in plotting it. Which function or method can I use to visualize this in Maple?

Thanks a lot!


Hi all,

I have this system

> system2hD := 0 = -d[1, 2], 0 = -d[2, 1], 0 = -delta*d[1, 2], 0 = -d[1, 1]-delta*d[1, 1], 0 = -delta*d[1, 1]-d[2, 2];
> solve({system2hD, delta <> 0, delta <> 1}, {d[1, 1], d[1, 2], d[2, 1], d[2, 2]});
      {d[1, 1] = 0, d[1, 2] = 0, d[2, 1] = 0, d[2, 2] = 0}

But, I hope to get the answers as {d[1, 1] = -delta*d[1, 1], d[1, 2] = 0, d[2, 1] = 0, d[2, 2] = -delta*d[1, 1]}. I think, I should not use the command "solve".

Can someone please advice and hepl me on this?



Hello all,

Yesterday, I upgraded to Mac OS X El Capitan.

Now, when working with Maple 2015, I feel the gui is very slow and sometimes irresponsive, when trying to scroll through my worksheets as well as through help pages (e.g., "help plot3d"). When I do the same within Maple 18, it works without any problems.

Does anybody else have the same issue?



Below is a calculation with 200 Volt and 100 Ω.
The output is 1 Ampere at -45 degrees.
This is useful for electrical circuit calculations, and I can get the right result on a TI-nspire.

However I can't make maple 2015 do it. It's resembling polar coordinates but I can't seem to find any info I can understand.



below is the same equation but in a picture so it can be read by humans:


Hopefully theres some simple comands that can help make this easy.


For example, I have a commutation table of finite Lie algebra. I'd like to extract some information from it (mainly, I'm interested in maximal dimension of abelian Lie subalgebra).

if eval(simplify( subs(a=2,subs(b= 5,f))))) - n = 0 then

      hello := union(hello, {f})

end if:

after subs(a=2,subs(b= 5,f))) to verify , some of hello return -n


why it is possible to pass the if condition statement?

if it is normal case, how to write correct if statement to ensure no -n 

I want to plot a cone in 3-d for any given axis vecttor, center and eccentricity.

Hello everybody

In the following attached file, I have used "fnormal" command to omit small numbers that are less than "1e-6" but when I run the maple, I see the numbers such as 2.10^(-11). What's the problem?

Thanks in advance.

Hello everyone, 


I'm currently taking a Chaos and Fractal Geometry class that did not have a pre-req of computer programming or knowledge of Maple, but I am apparently the only person in the class who has not taken a class/does not have this knowledge so my professor really flew by teaching the material. My sob story aside, I was hoping you great people would be able to help me out with (what are apparently) really basic procedures and plots while I try to read up on how to actaully do it myself (if anyone has a good supplement to recommend, I'm all ears!). Anyway, here are the one's that I'm stumped on:

  • "Write a Maple proc L that takes as input two lists and returns as output a set containing the terms they have in common (not necessarily in the same position). For example, L([1, 3, x, 5],[2, x, 5, 2, 1, 8]) should return [1, x, 5]."
    I'm thinking this is going to use some form of the intersection command, but I cannot for the life of me figure out how to set up the syntax
  • "Write a Maple program that implements the Euclidean algorithm to compute the gcd(x, y) for any natural numbers x, y (except x = y = 0). Your program should not just compute the gcd, but should do so by implementing the Euclidean algorithm directly (i.e. proc(x,y) RETURN(gcd(x,y)) end; is not what I am looking for here! :) )."
    If only he would've let me do the easy one :(
  • "Write a Maple program to plot the Pythagorean spiral. The program should take a single positive integer n as an argument and plot the spiral until the side of length n is reached"
    Not even a clue on how to approach this one. 


Thanks again to any and all help/recommendations you can make. I really appreciate it!

Hi there

I use Maple13 for plotting the surface of revolution of y=x^2 around the line y=1 on the interval [1,2]. But the distance between the surface 

and the vertical axis is ignored while there must be 1 unit distance.please specify the correct command.

Thanks for your cooperation


M. R. Yegan


What I want is quite simple but I have not seen it implemented anywhere yet. 

I have an explicit map F from the plane into itself. (not an ODE but simply a map) 

Then I have a set X, (something like a line segment or a rectangle in the plane) for which I 

really need to keep track of the images $F(X), F^2(X), F^3(X)$, and so on.

Is there a way to plot the image of a set in Maple? 

Thank you very much for your interests in the question. 





I am a new fellow of maple software.


I am trying to run an example of Poincare package example found in

But when i  wrote the commands found in this site, i got this error:  Error, unable to match delimiters 

The commands  are the following:

> restart;
> with(DEtools, poincare, generate_ic, zoom, hamilton_eqs);
> H := ((p1^2+p2^2)*(1/2))*((e^(2*q2+2*sqrt(3)*q1)+e^(2*q2-2*sqrt(3)*q1)+e^(-4*q2))*(1/24))-1/8;


> poincare('' '', stepsize=.05,iterations=5);
Error, unable to match delimiters 

                                        poincare('' '', stepsize=.05,iterations=5)

I would appreciate any helps.



if input x^2*y+x*y+x

how to output [x^2*y, x*y, x]

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