Hi there,

I have a function X that I am trying to plot a phase portrait for against it's derivative dX/dt. I currently have the code:

plot([X,diff(X,t),t=0..10],numpoints=1000) 

which sketches a graph but does not give any arrows to indicate direction.

Could anybody help?

Many thanks

Hi there,

I have a function defined as:

U:=-[0.25*exp(1/2*epsilon*t)*(1/v^2-1+exp(epsilon*t))^(-0.5)]*sin(4*t)

which I am trying to plot on a 2D graph of axes (t,u(t)).

In the specific case I have epsilon=1/10 and v=2

When I try plot(U), maple returns the error message:

Warning, unable to evaluate the function to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct

Could anybody help me out please?

Many thanks

Hi there,

I have an ode that I want to plot, I am trying to plot 2 different graphs on one graph and have tried using display but cannot seem to add a legend to it. Someone suggested adding a legend to each individual graph before combining them but I cannot find out how to add a legend to a DEplot. My code is as follows:

ode:=diff(u(t),t$2)-0.1*(1-64*u(t)^2)*diff(u(t),t$1)+16*u(t)=0

Q1:=v/4*sin(4*t)+epsilon*(1/8*(v-v^3)*t*sin(4*t)+v^3/128*(cos(4*t)-cos(12*t)))

A:=DEplot(ode,u(t),t=0..10, [[u(0)=0, D(u)(0)=v]], u=-0.5..0.5, linecolor=black, linestyle=dash, title="Numerical Solution"):

B:=plot(Q1, t=0..10, u=-0.5..0.5,color=blue, legend="Regular Perturbation Expansion"):

display([A,B],title="Comparing the regular perturbation expansion to the numerical solution")

Many thanks

Hi there,

Relatively new to maple (and programming all together). I am looking to try and make an if statement that performs several checks but I do not know which order to put them in.

Essentially I am trying to start out with i=1, max(Q)>0 and then perform a function, then add 1 to i and run it back through the test again. When my function changes from max(Q)>0 to max(Q)<=0 then I will have found a solution but only if i<330.

I am also unsure if I should put the test for i>330 before or after max(Q) test.

Thank you for any help