Mr. Robert Long

## 1409 Reputation

14 years, 262 days
Leeds, United Kingdom

## phase portrait...

Maple
Hi all I'd like to construct a phase portrait of a DE system with several different solutions on one plot. To do this I've been using odeplot for each solution and then displaying each plot with display(). Now I'd like for there to be arrows on each solutions, resulting in a phase portrait which will show the direction of phase flow for each orbit, but I couldn't find a way to add arrows to each individual plot. Is there a way to do that ? If not, is there a different approach to achieve this kind of phase portrait ? Thanks LR

## LerchPhi & polylog...

Maple
Greetings all restart; f := x->x^4: assume(n::integer): an := 1/Pi*int(f(x)*cos(n*x),x=-Pi..Pi): FaN1 := sum(an*cos(n*x),n=1..N); FaN2 := Sum(an*cos(n*x),n=1..N); On Maple 13, FaN1 and FaN2 are very different representations of this series. However, on Maple 11 they are the same (same as FN2 on Maple 13). How can I persuade Maple 13 to convert FaN2 to FaN1 ? Also, how can I persuade Maple 11 to convert aFN1 to FaN2 ?

## driven harmonic oscillator - amplitude &...

Maple
Hi all I'm trying to obtain an expression for oscillatory motion in terms of the long-run amplitude, phase angle and frequency of a driven oscillatory system: deq:=diff(x(t),t\$2)+lambda*diff(x(t),t)+omega[0]^2*x(t)=F[0]*sin(omega*t); The steady state solution I get from Maple is in this form ss:=((-omega[0]^2+omega^2)*sin(omega*t)+cos(omega*t)*omega*lambda)*F[0]/(omega^4+(lambda^2-2*omega[0]^2)*omega^2+omega[0]^4);

## convert set of parameters to assigned va...

Maple
Hi all I'm using a set of parameters, such as {a=1.b=2,c=3} to do various manipulations of an ODE system. Then later I want those parameters to be assigned their respective values, but I'd rather not have to do a:=1;b:=2;c:=3 Is there a way to do that ? Thanks LR

## Lost kernel connection...

Maple
This problem has ocurred a few times and is quite troublesome.
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