## 55 Reputation

3 years, 194 days

## Maple PDE solver...

Hello,

does Maple have a PDE solver? I want to solve the following inhomogeneous case of the heat equation:

diff(u(t,x,y,z),t)=k*Laplacian(u(t,x,y,z))+l*u(t,x,y,z)+m

with boundary conditions u(t,0,y,z)=u(t,L,y,z)=u(t,x,0,z)=u(t,x,L,z)=u(t,x,y,0)=u(t,x,y,L)=0. The initial condition is not fixed, as I want to try different cases. It will probably be some sinusoidal spatial function. I would prefer an analytic solution but I could live with a numerical one. If not in three spatial dimensions then even a solution with one dimension would be useful. I would appreciate any help.

Thank you.

## Plot residuals ...

Maple

y := t -> 0.7*sin(300*t);
filenm := "https://www.gw-openscience.org/GW150914data/P150914/fig2-unfiltered-template-reconstruction-H.txt";
K := ImportMatrix(filenm, source = Matlab, skiplines = 1);
plot([K[() .. (), [1, 3]], y(t)], t = 0.35 .. 0.4);

I want to plot the residuals for this. Any ideas how? Thanks.

## Numerical solution of differential equat...

Maple

I have:

dx6PN := 9836.535181*(1 - 2.890681911*x(t) + 4*Pi*x(t)^(3/2) + 3.753665653*x(t)^2 - 37.77895388*x(t)^(5/2) + (120.1000376 - (856*ln(16*x(t)))/105)*x(t)^3 + 54.24658055*x(t)^(7/2) + (9.292369248 - 23.08463043*ln(x(t)))*x(t)^4 + (540.5708789 - 102.446*ln(x(t)))*x(t)^(9/2) + (415.3887908 + 318.8547366*ln(x(t)))*x(t)^5 + (1549.709468 - 384.6723254*ln(x(t)))*x(t)^(11/2) + (2172.892557 + 407.4405529*ln(x(t)) + 33.2307*ln(x(t))^2)*x(t)^6)*x(t)^5

Ms := 0.0003214719000

xlow := 0.04672277118

tin := 4.125604512

I want to solve the following for t>tin to obtain xphi. I then want to plot xphi over the range tin to tin+1:

diff(x(t), t) = dx6PN, diff(xphi(t), t) = (x(t)^(3/2))/Ms, x(0) = xlow, xphi(tin) = 0

I could use some help.

## Import and plot data...

Maple

Hi!

I want to import the data included here to my Maple code:

https://www.gw-openscience.org/GW150914data/P150914/fig2-unfiltered-template-reconstruction-H.txt

There are 3 columns of data: time, NR strain, Reconstructed strain. I am not interested in the middle column; I want to plot the reconstructed strain as a function of time. I could use some help.

Cheers!

## Solve one-variable equation...

Maple

Hello,

I have the following function:

y:=t->808.2213240*(1 - 0.63*(1993551437/1601983488 - sqrt(3)/2)^0.3)*(1 - 335345*(45188/147189 - 53/(4820*ln(2)))*335345^(131537/203808)*131537^(72271/203808)*(1 - 1/(1 + (203808*exp(-677.0138344*t))/131537)^(131537/203808))/34603964738)

I want to solve for t when y(t)=196.9594856. I tried solve(y(t)=196.9594856,t) and it took several minutes of still evaluating before I gave up. Any ideas? Cheers.

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