{VERSION 2 3 "IBM INTEL NT" "2.3" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 1 2 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "Text \+ Output" -1 2 1 {CSTYLE "" -1 -1 "Courier" 1 10 0 0 255 1 0 0 0 0 0 1 3 0 0 }1 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "R3 Font 0" -1 256 1 {CSTYLE "" -1 -1 "Helvetica" 1 12 128 0 128 1 2 1 2 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "R3 Font 2" -1 257 1 {CSTYLE "" -1 -1 "Courier" 1 11 0 128 128 1 2 1 2 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }} {SECT 0 {EXCHG {PARA 0 "" 0 "" {TEXT -1 84 "Wave Packet Problem \+ BMsteer.MWS" }}{PARA 0 "" 0 "" {TEXT -1 82 "'steering a beam' in Multiple Source Interference 8/25/95 after BMWidth.ms" }}{PARA 0 "" 0 "" {TEXT -1 84 "Lear ning objectives: Translation of equation for 2D wave to off-origin sou rce points" }}{PARA 0 "" 0 "" {TEXT -1 77 " \+ Physical intuition regarding interference" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 89 "Show a radiated beam bein g 'steered' by changing the phase shift between adjacent sources" }} {PARA 0 "" 0 "" {TEXT -1 37 " " }} {PARA 0 "" 0 "" {TEXT -1 16 "MAPLE: animate3d" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 8 "Remarks:" }}{PARA 0 "" 0 " " {TEXT -1 47 "Takes some minutes to execute on most machines." }} {PARA 0 "" 0 "" {TEXT -1 65 "Array of sources extends along the x-axis , centered at the origin" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 " " 0 "" {TEXT -1 48 "Wavelength, spacing, x, and y could be in meters" }}{PARA 0 "" 0 "" {TEXT -1 35 "k0 = wave number = 2 Pi/ wavelength" }} {PARA 0 "" 0 "" {TEXT -1 34 "spacing = distance between sources" }} {PARA 0 "" 0 "" {TEXT -1 44 "xmax, ymax used to set plot range dimensi ons" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "> " 0 " " {MPLTEXT 1 0 8 "restart;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }} {PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "with(plots):" }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 16 "wavelength:=1.0;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 25 "k0:=628/(100*wavelength);" }}}{EXCHG {PARA 0 "> " 0 " " {MPLTEXT 1 0 13 "NrSources:=4;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 14 "spacing:=6/10;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 10 "Atotal:=0;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 25 "for j from 1 to NrSources" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 7 " do" }} {PARA 0 "> " 0 "" {MPLTEXT 1 0 106 " m:=(2*j-5)/2: \+ # m = \{-3/2 , -1/2, 1/2, 3/2\} for four sou rces" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 72 " r:=((x-m*spacing) ^2+y^2)^0.5: # distance from source to (x,y)" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 41 " Atotal:=Atotal+cos(k0*r-m*phi):" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 9 " od:" }}}{EXCHG {PARA 2 "" 0 "" {TEXT -1 1 "\n" }}{PARA 0 "" 0 "" {TEXT -1 87 "Atotal:=A[1]+A[2]+...+A[NrSou rces]: # amplitude pattern at t=0 due to all four sources" }}{PARA 2 "" 0 "" {TEXT -1 1 "\n" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 57 "### Animate the effect of ch anging source separations ###" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 38 "xmax:=4: ymax:=4: #Set plot area scale" }}}{EXCHG {PARA 0 "" 0 " " {TEXT -1 98 "The orientation is theta=0, phi =0 (phi = any), so the \+ x-axis goes down as we look from the z-axis" }}{PARA 2 "" 0 "" {TEXT -1 1 "\n" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 195 " animate3d(Atotal, x=- xmax..xmax, y=-ymax/5..9*ymax/5,phi=0/10..14/10, grid=[35,35],style=pa tchnogrid, shading=zgreyscale, scaling=constrained, orientation=[0,Pi/ 4], tickmarks=[0,0,0],frames=10);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}} {MARK "14 0 0" 0 }{VIEWOPTS 1 1 0 1 1 1803 }