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%!PS-Adobe-3.0 % % ******************************************************************************** % % Figure 7.8(d) 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: June 9, 1999 % % ******************************************************************************** % % A latent image in the superposition of 2 line gratings - first layer only: % % The grating parameters are as follows: % % theta1, theta2 - the grating angles, in degrees. % p1, p2 - the respective grating periods, in deciinches. % xshifti - the period-shifts for the i-th grating, in terms of period fractions. % len - the length of each of the gratings, in centiinches. % wid - the width of each of the gratings, in centiinches. % % ******************************************************************************** % /inch {72 mul} def /centiinch {0.72 mul} def 0.7 centiinch setlinewidth /len 170 def % grating length in centiinches /wid 120 def % grating width in centiinches /len2 len 2 div def /wid2 wid 2 div def /starwidth 0.75 inch def /starwidth2 0.75 inch 2 div def /starside % From blue PS book p. 51 {starwidth 0 inch lineto % add line to path currentpoint translate % move origin 120 rotate } def /star {moveto currentpoint translate 3 {starside} repeat closepath } def /Helvetica findfont 9 scalefont setfont -1 inch 1.45 inch translate gsave % ******************************** Fig. (d): /theta1 0 def % angle of grating A /theta2 0 def % angle of grating B /rot 0 def % general rotation to prevent printer artifacts /p1 3 def % period of grating A /p2 3 def % period of grating A /xshift1 0 p1 mul def % period-shift of grating A (e.g. 0.5) /xshift2 6.5 p2 mul def % period-shift of grating B (e.g. 0.5) % Draw grating A: gsave 5 inch 6 inch translate theta1 rot add rotate gsave newpath 0 p1 len % draw lines {centiinch len2 p1 div round p1 mul xshift1 sub centiinch sub wid2 centiinch neg moveto 0 centiinch wid centiinch rlineto} for stroke -0.95 inch -0.6 inch moveto (A) show % Make a triangular hole within grating A: newpath 1 setgray % white starwidth2 neg -0.4 inch star fill grestore % Fill the triangular hole with a half-period shifted grating: gsave /xshift1 0.5 p1 mul def % period-shift of grating A (e.g. 0.5) newpath starwidth2 neg -0.4 inch star clip starwidth2 0.4 inch translate % return to initial position before the star newpath 0 p1 len % draw lines {centiinch len2 p1 div round p1 mul xshift1 sub centiinch sub wid2 centiinch neg moveto 0 centiinch wid centiinch rlineto} for stroke grestore grestore gsave 5 inch 6 inch translate -0.05 inch -1.08 inch moveto /Times-Roman findfont 12 scalefont setfont ((d)) show grestore gsave 2.75 inch 1 inch translate 0 inch 0 inch moveto /Times-Bold findfont 12 scalefont setfont (Figure 7.8(d)) 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 1.7 inch -0.65 inch moveto ((First layer only.)) show grestore grestore showpage