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MaplePrimes Activity

These are questions asked by cosmicstring

Is there a way of extracting the terms of an expression with a certain dependence?

For example:

If I have,


I need to have,


parts separately.

(Of course, a way other than taking derivative.)

I am trying to save an array plot to an eps file. My code is the following:

restart: with(plots): currentdir("G:/"): plotsetup(default):
alpha := [.2, .25, .3, .35, .4]:
beta := -0.1e-1:mygamma := -1:delta := 0.1e-1:start := 0:finish := 20:

for i to 5 do
 eqn1 := diff(x(t), t)-x(t)*(alpha[i]-beta*y(t));
 eqn2 := diff(y(t), t)-y(t)*(mygamma-delta*x(t));
 solt[i] := dsolve([eqn1 = 0, eqn2 = 0, x(start) = 80, y(start) = 40...

I am trying to solve two differential equations numericaly:

I need to find the Killing vectors of a metric.

I initiate the session as

> restart;
> with(DifferentialGeometry); with(Tensor); with(LieAlgebras);
> DGsetup([t, r, z, phi], M);

and enter my metric as

M > g1 := evalDG(-dt &t dt ...);

I do not have an unknown function in my metric but I have two free parameters (e.g. a and b).

I use

M > K1 := KillingVectors(g1, parameters = [a, b]);

I'd like to hear a sound alert when Maple 15 (64bit version, on Windows 7 64bit) finishes the execution of a command.

For example, I have a very lengthy function to simplify. I use


but it takes too long. It would be very helpful for me to hear a sound when this simplification finishes so that I can come back to see the result and go on.

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