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MaplePrimes Activity

These are questions asked by Jarekkk

If you look at Maple help on Grid[Launch] command there is an example of checking the prime numbers.

I do not understand why the timingData variable is empty after specifying it in exports parameter.

When I do not specify it in the exports parameter, the timingData variable has the same value as it had before calling Launch command.

I have been investigating Predator-Prey spatial models, e.g.

diff(N(x, t), t) = r*N(x, t)*(1-N(x, t)/K(x, t))-a*N(x, t)*P(x, t)+d[1]*(diff(N(x, t), x, x))

diff(P(x, t), t) = P(x, t)*(b*N(x, t)-c)+d[2]*(diff(P(x, t), x, x))


Hi everyone,

I have a differential equation

      diff(N(t), t) = r*N(t)*(1-N(t)/K) - p(N(t)),    N(0) = N0


      p(x):=piecewise(0, x<0, S/(N_crit)*x, 0<= x<N_crit, S)


This equation represents the population growth model where the predator is present.


can you tell me, please, how I can create labels when plot command (and its labels option) doesn't work?


Try these examples:

Ex1:  plot(1/(3+exp(x)), x = 0 .. 10, labels = ["x", "y"]);

Ex2:  plot(1/(3+exp(-x)), x = 0 .. 10, labels = ["x", "y"]);

In first case everything is OK, in second "y" label doesn't appear and I can't manage to put it into plot.

Thank you.


PS: I'm using Maple 13.


Does anybody know how precise the eigenvalues (or the eigenvectors) of some Matrix are (when I use Eigenvalues(Matrix))?

Let's assume Digits=15. Can I have any certainty that the computed eigenvalues are precise to some (15??) digits?

I don't know how Maple computes them but if I suppose several (many) arithmetic operations then the error can move "upward".

Am I wrong? Thank you for all your suggestions.

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