%!

% procedures

/pagebegin {  
/A exch def
/x A 0 get def
/y A 1 get def
gsave 
72 dup scale 
x y translate
0.5 72 div setlinewidth
} def 

/pageend { 
grestore showpage 
} def 

% array [x y r theta]]
/circle {8 dict begin
/A exch def
/x A 0 get def
/y A 1 get def
/r A 2 get def
/theta A 3  get def
/c 270 def 
/n 64 def
newpath
r c cos mul x add r c sin mul y add moveto
n{
/c c theta n div add def
r c cos mul x add r c sin mul y add lineto
} repeat
x y lineto
end} def

% array [x y a b theta]
/ellipse {9 dict begin
/A exch def
/x A 0 get def
/y A 1 get def
/a A 2 get def
/b A 3  get def
/theta A 4 get def
/c 0 def 
/n 64 def
newpath
a c cos mul x add b c sin mul y add moveto
n{
/c c theta n div add def
a c cos mul x add b c sin mul y add lineto
} repeat
end} def


% colors

/black { 
0 0 0 setrgbcolor
}def

/yellow { 
1 1 0 setrgbcolor 
} def 

/red {
1 0 0 setrgbcolor
} def 

/blue {
0 1 1 setrgbcolor
} def 

/white {
1 1 1 setrgbcolor
} def

% Fonts

/largefont {
/Times-Roman findfont
0.32 scalefont
setfont } def

/normalfont {
/Times-Roman findfont
0.22 scalefont
setfont } def

/smallfont {
/Times-Roman findfont
0.16 scalefont
setfont}def

/polygon { 2 dict begin 
/poly exch def 
/n poly length def 
poly 0 get aload pop moveto 
1 1 n 1 sub { 
/i exch def
poly i get aload pop lineto 
} for 
closepath
end} def 

/rotateA{
/A exch def
/x A 0 get def
/y A 1 get def
/r A 2 get def
/theta A 3 get def
/n theta neg def

7{
/n n theta add def
newpath
x y moveto
r n cos mul x add r n sin mul y add lineto
stroke}repeat

}def

/rotation

{7 dict begin
/rotate exch def
/n rotate length def
/a 0 def

 n{
 /theta rotate a get def  
 /alpha 90 theta sub 2 div def
 /a a 1 add def
 newpath
 2 alpha sin alpha cos div mul 1 moveto
 0 -1 lineto
 stroke
}repeat

end}def

/circles

{7 dict begin
/rotate exch def
/n rotate length def
/a 0 def

 n{
 /theta rotate a get def  
 /a a 1 add def
 newpath theta cos -1 moveto theta cos 1 lineto stroke
 newpath theta cos neg -1 moveto theta cos neg 1 lineto stroke
}repeat

end}def

/rays

{7 dict begin
/ray exch def
/n ray length def
/a 0 def

 n{
 /theta ray a get def  
 /a a 1 add def
 newpath theta cos theta sin moveto 0 0 lineto stroke
 newpath theta cos theta sin moveto theta cos neg theta sin lineto stroke
 newpath theta cos theta sin moveto 0 1 theta sin div lineto stroke
 newpath theta cos neg theta sin moveto 0 1 theta sin div lineto stroke 

}repeat

end}def

% array [x y r theta]]
/circleray {8 dict begin
/A exch def
/x A 0 get def
/y A 1 get def
/r A 2 get def
/theta A 3  get def
/c 270 theta sub def 
/n 10 def
newpath
n{
/c c theta add def
x y moveto
r c cos mul x add r c sin mul y add lineto
} repeat
end} def

/latitude

{7 dict begin
/lat exch def
/n lat length def
/a 0 def

 n{
 /theta lat a get def  
 /a a 1 add def
 /b 45 cos theta cos sub def
 /c theta sin 45 cos sub def
 /d b b mul c c mul add sqrt def
 /r 45 cos 45 sin div theta 45 sub 2 div cos d mul sub def
 newpath [0 0 r 360 45 sin mul 2 div] circle stroke
 newpath [0 0 r 360 45 sin mul 2 div neg] circle stroke
 
 }repeat

end}def


[3 7] pagebegin
black
[[-3 4] [3 4] [3 -2] [-3 -2]] polygon fill

white
[0 0 45 cos 45 sin div 360 45 sin mul 2 div] circle stroke
[0 0 45 cos 45 sin div 360 45 sin mul 2 div neg] circle stroke
[50 55 60 65 70 75 80 85] latitude
blue
[0 0 45 cos 45 sin div 36 45 sin mul 2 div] circleray stroke
[0 0 45 cos 45 sin div 36 45 sin mul 2 div neg] circleray stroke
pageend