## 255 Reputation

3 years, 134 days

## Long waiting time of plotting the chen–g...

Maple

Hello do u know how to make this code more optimal? this is very long time to plot.

g := evalf((Beta(1/4, 1/4)/2)^4);

A := Pi*r*cos(theta) - Re(WeierstrassZeta(r*exp(theta*I), g, 0) + Pi*WeierstrassPPrime(r*exp(theta*I), g, 0)/g);
B := Pi*r*sin(theta) + Im(WeierstrassZeta(r*exp(theta*I), g, 0) - Pi*WeierstrassPPrime(r*exp(theta*I), g, 0)/g);
C := sqrt(6*Pi/g)*Re(WeierstrassP(r*exp(theta*I), g, 0));

plot3d([A, B, C], r = 1/5 .. 4/5, theta = -Pi .. Pi, view = [-8 .. 8, -8 .. 8, -8 .. 8], shading = zhue, grid = [200, 200]);

## How to get revolution surface of polar c...

Maple

Hi! Do you know how can I plot revolution of this curve:

plot(1 + 1/4*sin(8*(1 + 1/8*sin(16*(1 + 1/16*sin(32*t))))), t = 0 .. 2*Pi, coords = polar)

to get a wrinkled torus like this:

Do u have any idea? (I've tried to convert this polar curve to cartesian coords but I don't get it)

## Belousov–Zhabotinsky equation ...

Maple

Hi! Do you know maybe how to solve equation with Laplace operator in Maple like BZ equation?

restart;
a := 0.75;
rho := u(t) + v(t) + w(t);
ode := diff(u(t), t) = 10*Delta(u(t)) + u*(-a*v - rho + 1);
ode1 := diff(v(t), t) = 10*Delta(v(t)) + v*(-a*w - rho + 1);
ode2 := diff(w(t), t) = 10*Delta(w(t)) + w*(-a*u - rho + 1);

Edit: Sorry I guess it should be function of three variables so u,v,w depends on (x,y,z) not strictle from time

I am wondering how to animate something like this from BZ equation:

## Area under dataset...

Maple

Hi! do you know any effective method to count area under this function given by dataset points? (I counted this by approximation by trapezes)

Edit: PolyFit is ok the best what I have done

Edit2: triangulation is the best (just add all triangles)

## How to divide array?...

Maple

Hi! Do you know how to divide this array from .txt data to take separately these numbers? (I have over one thousands of these so I don't want to rewrite)

PS this is 1x1 I want to make 1x8

["0,00244140625;8,07751097960625;-3,555908203125E-05;0,002166748046875;1;1;0,0056941700604248;-0,0101856454842773;100 µA"]

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