## Asymptote using graph3.asy – fig0150

Category: Asymptote,Examples 3D,graph3.asyPh. Ivaldi @ 17 h 11 min

 (Compiled with Asymptote version 2.14svn-r5318)

settings.render=0;
import graph3;
size(10cm);

currentprojection=orthographic(4,2,4);

real r(real Theta, real Phi){return 1+0.5*(sin(2*Theta)*sin(2*Phi))^2;}
triple f(pair z) {return r(z.x,z.y)*expi(z.x,z.y);}

pen[] pens(triple[] z)
{
return sequence(new pen(int i) {
real a=abs(z[i]);
return a < 1+1e-3 ? black : interp(blue, red, 2*(a-1));
},z.length);
}

surface s=surface(f,(0,0),(pi,2pi),100,Spline);
// Interpolate the corners, and coloring each patch with one color
// produce some artefacts
draw(s,pens(s.cornermean()));

if(!is3D())
shipout(bbox(3mm,Fill(black)));



Étiquettes : , , , , ,

## Asymptote using graph3.asy – fig0160

Category: Asymptote,Examples 3D,graph3.asyPh. Ivaldi @ 18 h 11 min

 (Compiled with Asymptote version 2.14svn-r5318)

settings.render=0;
import graph3;
size(10cm);

currentprojection=orthographic(4,2,4);

real r(real Theta, real Phi){return 1+0.5*(sin(2*Theta)*sin(2*Phi))^2;}
triple f(pair z) {return r(z.x,z.y)*expi(z.x,z.y);}

pen[][] pens(triple[][] z)
{
pen[][] p=new pen[z.length][];
for(int i=0; i < z.length; ++i) {
triple[] zi=z[i];
p[i]=sequence(new pen(int j) {
real a=abs(zi[j]);
return a < 1+1e-3 ? black : interp(blue, red, 2*(a-1));},
zi.length);
}
return p;
}

surface s=surface(f,(0,0),(pi,2pi),100,Spline);
// Here we interpolate the pens, this looks smoother, with fewer artifacts
draw(s,mean(pens(s.corners())));

if(!is3D())
shipout(bbox(3mm,Fill(black)));



Étiquettes : , , , , ,

## Asymptote using graph3.asy – fig0170

Category: Asymptote,Examples 3D,graph3.asyPh. Ivaldi @ 19 h 11 min

 (Compiled with Asymptote version 2.14svn-r5318)

settings.render=0;
import graph3;
size(10cm);

currentprojection=orthographic(4,2,4);

real r(real Theta, real Phi){return 1+0.5*(sin(2*Theta)*sin(2*Phi))^2;}
triple f(pair z) {return r(z.x,z.y)*expi(z.x,z.y);}

pen[][] pens(triple[][] z)
{
pen[][] p=new pen[z.length][];
for(int i=0; i < z.length; ++i) {
triple[] zi=z[i];
p[i]=sequence(new pen(int j) {
real a=abs(zi[j]);
return a < 1+1e-3 ? black : interp(blue, red, 2*(a-1));},
zi.length);
}
return p;
}

surface s=surface(f,(0,0),(pi,2pi),100,Spline);
// Here we determine the colors of vertexes (vertex shading).
// Since the PRC output format does not support vertex shading of Bezier surfaces, PRC patches
// are shaded with the mean of the four vertex colors.
s.colors(pens(s.corners()));
draw(s);

if(!is3D())
shipout(bbox(3mm,Fill(black)));



Étiquettes : , , , , ,

## Asymptote using graph3.asy – fig0180

Category: Asymptote,Examples 3D,graph3.asyPh. Ivaldi @ 20 h 11 min

 The spherical harmonics are the angular portion of the solution to Laplace's equation in spherical coordinates where azimuthal symmetry is not present. The spherical harmonics are defined by: where and is the Legendre polynomial. Source (Compiled with Asymptote version 2.14svn-r5318)

import palette;
import math;
import graph3;

typedef real fct(real);
typedef pair zfct2(real,real);
typedef real fct2(real,real);

real binomial(real n, real k)
{
return gamma(n+1)/(gamma(n-k+1)*gamma(k+1));
}

real factorial(real n) {
return gamma(n+1);
}

real[] pdiff(real[] p)
{ // p(x)=p[0]+p[1]x+...p[n]x^n
// retourne la dérivée de p
real[] dif;
for (int i : p.keys) {
if(i != 0) dif.push(i*p[i]);
}
return dif;
}

real[] pdiff(real[] p, int n)
{ // p(x)=p[0]+p[1]x+...p[n]x^n
// dérivée n-ième de p
real[] dif={0};
if(n >= p.length) return dif;
dif=p;
for (int i=0; i < n; ++i)
dif=pdiff(dif);
return dif;
}

fct operator *(real y, fct f)
{
return new real(real x){return y*f(x);};
}

zfct2 operator +(zfct2 f, zfct2 g)
{// Défini f+g
return new pair(real t, real p){return f(t,p)+g(t,p);};
}

zfct2 operator -(zfct2 f, zfct2 g)
{// Défini f-g
return new pair(real t, real p){return f(t,p)-g(t,p);};
}

zfct2 operator /(zfct2 f, real x)
{// Défini f/x
return new pair(real t, real p){return f(t,p)/x;};
}

zfct2 operator *(real x,zfct2 f)
{// Défini x*f
return new pair(real t, real p){return x*f(t,p);};
}

fct fct(real[] p)
{ // convertit le tableau des coefs du poly p en fonction polynôme
return new real(real x){
real y=0;
for (int i : p.keys) {
y += p[i]*x^i;
}
return y;
};
}

real C(int l, int m)
{
if(m < 0) return 1/C(l,-m);
real OC=1;
int d=l-m, s=l+m;
for (int i=d+1; i <=s ; ++i) OC *= i;
return 1/OC;
}

int csphase=-1;
fct P(int l, int m)
{ // Polynôme de Legendre associé
// http://mathworld.wolfram.com/LegendrePolynomial.html
if(m < 0) return (-1)^(-m)*C(l,-m)*P(l,-m);
real[] xl2;
for (int k=0; k <= l; ++k) {
xl2.push((-1)^(l-k)*binomial(l,k));
if(k != l) xl2.push(0);
}
fct dxl2=fct(pdiff(xl2,l+m));
return new real(real x){
return (csphase)^m/(2^l*factorial(l))*(1-x^2)^(m/2)*dxl2(x);
};
}

zfct2 Y(int l, int m)
{// http://fr.wikipedia.org/wiki/Harmonique_sph%C3%A9rique#Expression_des_harmoniques_sph.C3.A9riques_normalis.C3.A9es
return new pair(real theta, real phi) {
return sqrt((2*l+1)*C(l,m)/(4*pi))*P(l,m)(cos(theta))*expi(m*phi);
};
}

real xyabs(triple z){return abs(xypart(z));}

size(16cm);
currentprojection=orthographic(0,1,1);

zfct2 Ylm;

triple F(pair z)
{
//   real r=0.75+dot(0.25*I,Ylm(z.x,z.y));
//   return r*expi(z.x,z.y);
real r=abs(Ylm(z.x,z.y))^2;
return r*expi(z.x,z.y);
}

int nb=4;
for (int l=0; l < nb; ++l) {
for (int m=0; m <= l; ++m) {
Ylm=Y(l,m);

surface s=surface(F,(0,0),(pi,2pi),60);
s.colors(palette(s.map(xyabs),Rainbow()));

triple v=(-m,0,-l);
draw(shift(v)*s);
label("$Y_"+ string(l) + "^" + string(m) + "$:",shift(X/3)*v);
}
}



## Official Asymptote example – sphericalharmonic

Category: Asymptote,Official Gallery One-PagerPh. Ivaldi @ 5 h 57 min

 (Compiled with Asymptote version 2.14svn-r5318)
/* This code comes from The Official Asymptote Gallery */

import graph3;
import palette;
size(200);

currentprojection=orthographic(4,2,4);
currentlight=Viewport;

real r(real theta, real phi) {return 1+0.5*(sin(2*theta)*sin(2*phi))^2;}

triple f(pair z) {return r(z.x,z.y)*expi(z.x,z.y);}

surface s=surface(f,(0,0),(pi,2pi),50,Spline);