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%!PS-Adobe-3.0
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% ********************************************************************************
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% Figure 8.16 from the book: "The Theory of the Moire Phenomenon"
% by I. Amidror, published by Kluwer Academic Publishers, 1999.
%
% * * * Copyright (c) 1999 EPFL * * *
%
% Author: I. Amidror
%
% Modified: July 15, 1999
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% ********************************************************************************
%
% (a), (b): Superpositions of 4 identical dot-screens:
%
% The screen parameters for each superposition are as follows:
%
% theta1,...,theta4 - the screen angles, in degrees.
% p1,...,p4 - the respective screen periods (main direction), in deciinches.
% p1y,...,p4y - the respective screen periods (perpendicular direction), in
% deciinches.
% xshifti, yshifti - the respective period-shifts for the i-th screen, in terms
% of period fractions.
% len - the length (and width) of each of the screens, in centiinches.
%
% ********************************************************************************
%
/inch {72 mul} def
/centiinch {0.72 mul} def
1 centiinch setlinewidth
1 setlinecap
/len 300 def % screen length in centiinches
/len2 len 2 div def
% ********************************** Fig. (a):
/theta1 0 def % angle of screen A
/theta2 22.5 def % angle of screen B
/theta3 45 def % angle of screen C
/theta4 67.5 def % angle of screen D
/rot 0 def % general rotation to prevent printer artifacts
/p1 3 def % period of screen A
/p2 3 def % period of screen B
/p3 3 def % period of screen C
/p4 3 def % period of screen D
/p1y 3 def % period of screen A (in the perpendicular direction)
/p2y 3 def % period of screen B (in the perpendicular direction)
/p3y 3 def % period of screen C (in the perpendicular direction)
/p4y 3 def % period of screen D (in the perpendicular direction)
/xshift1 0 p1 mul def % x period-shift of screen A (e.g. 0.5)
/yshift1 0 p1y mul def % y period-shift of screen A (e.g. 0.5)
/xshift2 0 p2 mul def % x period-shift of screen B
/yshift2 0 p2y mul def % y period-shift of screen B
/xshift3 0 p3 mul def % x period-shift of screen C
/yshift3 0 p3y mul def % y period-shift of screen C
/xshift4 0 p4 mul def % x period-shift of screen D
/yshift4 0 p4y mul def % y period-shift of screen D
1.7 inch 6.3 inch translate
gsave
/Helvetica findfont
10 scalefont setfont
% Draw screen A:
gsave
2.5 inch 2.5 inch translate
theta1 rot add rotate
0 p1y len % draw rows of dots
{newpath
/ysave exch centiinch len2 p1y div round p1y mul yshift1 sub centiinch sub def
0 p1 len % draw a row of dots
{centiinch len2 p1 div round p1 mul xshift1 sub centiinch sub ysave moveto
0 0 rlineto} for
stroke
} for
-1.62 inch 1.3 inch moveto
(A) show
grestore
% Draw screen B:
gsave
2.5 inch 2.5 inch translate
theta2 rot add rotate
0 p2y len % draw rows of dots
{newpath
/ysave exch centiinch len2 p2y div round p2y mul yshift2 sub centiinch sub def
0 p2 len % draw a row of dots
{centiinch len2 p2 div round p2 mul xshift2 sub centiinch sub ysave moveto
0 0 rlineto} for
stroke
} for
-1.62 inch 1.3 inch moveto
(B) show
grestore
% Draw screen C:
gsave
2.5 inch 2.5 inch translate
theta3 rot add rotate
0 p3y len % draw rows of dots
{newpath
/ysave exch centiinch len2 p3y div round p3y mul yshift3 sub centiinch sub def
0 p3 len % draw a row of dots
{centiinch len2 p3 div round p3 mul xshift3 sub centiinch sub ysave moveto
0 0 rlineto} for
stroke
} for
-1.62 inch 1.3 inch moveto
(C) show
grestore
% Draw screen D:
gsave
2.5 inch 2.5 inch translate
theta4 rot add rotate
0 p4y len % draw rows of dots
{newpath
/ysave exch centiinch len2 p4y div round p4y mul yshift4 sub centiinch sub def
0 p4 len % draw a row of dots
{centiinch len2 p4 div round p4 mul xshift4 sub centiinch sub ysave moveto
0 0 rlineto} for
stroke
} for
-1.62 inch 1.3 inch moveto
(D) show
grestore
gsave
2.5 inch 0 inch translate
-1.6 inch 0.4 inch moveto
/Times-Roman findfont
12 scalefont setfont
((a)) show
grestore
grestore
% ********************************** Fig. (b):
/theta1 0 def % angle of screen A
/theta2 22.5 def % angle of screen B
/theta3 45 def % angle of screen C
/theta4 67.5 def % angle of screen D
/rot 0 def % general rotation to prevent printer artifacts
/p1 3 def % period period of screen A
/p2 3 def % period period of screen B
/p3 3 def % period period of screen C
/p4 3 def % period period of screen D
/p1y 3 def % period of screen A (in the perpendicular direction)
/p2y 3 def % period of screen B (in the perpendicular direction)
/p3y 3 def % period of screen C (in the perpendicular direction)
/p4y 3 def % period of screen D (in the perpendicular direction)
/xshift1 0.5 p1 mul def % x period-shift of screen A (e.g. 0.5)
/yshift1 0.5 p1y mul def % y period-shift of screen A (e.g. 0.5)
/xshift2 0.5 p2 mul def % x period-shift of screen B
/yshift2 0.5 p2y mul def % y period-shift of screen B
/xshift3 0.5 p3 mul def % x period-shift of screen C
/yshift3 0.5 p3y mul def % y period-shift of screen C
/xshift4 0.5 p4 mul def % x period-shift of screen D
/yshift4 0.5 p4y mul def % y period-shift of screen D
0 inch -4.45 inch translate
gsave
/Helvetica findfont
10 scalefont setfont
% Draw screen A:
gsave
2.5 inch 2.5 inch translate
theta1 rot add rotate
0 p1y len % draw rows of dots
{newpath
/ysave exch centiinch len2 p1y div round p1y mul yshift1 sub centiinch sub def
0 p1 len % draw a row of dots
{centiinch len2 p1 div round p1 mul xshift1 sub centiinch sub ysave moveto
0 0 rlineto} for
stroke
} for
-1.62 inch 1.3 inch moveto
(A) show
grestore
% Draw screen B:
gsave
2.5 inch 2.5 inch translate
theta2 rot add rotate
0 p2y len % draw rows of dots
{newpath
/ysave exch centiinch len2 p2y div round p2y mul yshift2 sub centiinch sub def
0 p2 len % draw a row of dots
{centiinch len2 p2 div round p2 mul xshift2 sub centiinch sub ysave moveto
0 0 rlineto} for
stroke
} for
-1.62 inch 1.3 inch moveto
(B) show
grestore
% Draw screen C:
gsave
2.5 inch 2.5 inch translate
theta3 rot add rotate
0 p3y len % draw rows of dots
{newpath
/ysave exch centiinch len2 p3y div round p3y mul yshift3 sub centiinch sub def
0 p3 len % draw a row of dots
{centiinch len2 p3 div round p3 mul xshift3 sub centiinch sub ysave moveto
0 0 rlineto} for
stroke
} for
-1.62 inch 1.3 inch moveto
(C) show
grestore
% Draw screen D:
gsave
2.5 inch 2.5 inch translate
theta4 rot add rotate
0 p4y len % draw rows of dots
{newpath
/ysave exch centiinch len2 p4y div round p4y mul yshift4 sub centiinch sub def
0 p4 len % draw a row of dots
{centiinch len2 p4 div round p4 mul xshift4 sub centiinch sub ysave moveto
0 0 rlineto} for
stroke
} for
-1.62 inch 1.3 inch moveto
(D) show
grestore
gsave
2.5 inch 0 inch translate
-1.6 inch 0.4 inch moveto
/Times-Roman findfont
12 scalefont setfont
((b)) show
grestore
grestore
gsave
0.25 inch -0.3 inch translate
0 inch 0 inch moveto
/Times-Bold findfont
12 scalefont setfont
(Figure 8.16) show
/Times-Roman findfont
12 scalefont setfont
( from the book: ) show
/Times-Italic findfont
12 scalefont setfont
(The Theory of the Moire) show
-0.06 inch 0 inch rmoveto
(\302 Phenomenon) show
/Times-Roman findfont
12 scalefont setfont
0 inch -0.25 inch moveto
( by I. Amidror, published by Kluwer Academic Publishers, 1999.) show
grestore
showpage