Blame view

Giac_maj/giac-1.4.9/examples/geo/terre.cas 1017 Bytes
6663b6c9   adorian   projet complet av...
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
  // if (type(theta)!=DOM_FLOAT){ theta:=evalf(pi/2); };
  theta:=evalf(pi/2);
  latitude:=evalf(45/360*2*pi);
  erase3d();
  O:=point(0,0,0);
  theta_aphelie:=evalf(13/365*2*pi);
  S:=point(cos(theta_aphelie),sin(theta_aphelie),0);
  S1:=point(-cos(theta_aphelie),-sin(theta_aphelie),0);
  a:=5.0;
  E:=0.2;
  b:=a*sqrt(1-E^2);
  T:=point(cos(theta_aphelie)*a*cos(theta)+sin(theta_aphelie)*b*sin(theta),-sin(theta_aphelie)*a*cos(theta)+cos(theta_aphelie)*b*sin(theta),0);
  obliquite:=evalf(23.45/360*2*pi);
  R:=2.0;
  axe_dir:=[sin(obliquite),0,cos(obliquite)];
  sphere(T,R,axe_dir);
  equateur:=cercle(T-1.1*R*[0,1,0],T+1.1*R*[0,1,0],T+1.1*R*[-cos(obliquite),0,sin(obliquite)]);
  valence(t):=1.1*R*[cos(obliquite)*cos(latitude)*cos(t)+sin(obliquite)*sin(latitude),cos(latitude)*sin(t),-sin(obliquite)*cos(latitude)*cos(t)+cos(obliquite)*sin(latitude)];
  v0:=valence(0);
  vpi2:=valence(pi/2);
  vpi:=valence(pi);
  axe:=segment(T-2*R*axe_dir,T+2*R*axe_dir);
  ST:=segment(S,T);
  ellipse(S,S1,T);
  P:=perpendiculaire(T,ST);
  parall:=cercle(T+v0,T+vpi,T+vpi2);