{VERSION 2 3 "APPLE_68K_MAC" "2.3" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 }{CSTYLE "" -1 256 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 } {CSTYLE "" -1 257 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 }{CSTYLE "" -1 258 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 }{CSTYLE "" -1 259 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "" 0 256 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 }3 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "" 0 257 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 }3 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "" 0 258 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "" 0 259 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 }3 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }} {SECT 0 {EXCHG {PARA 256 "" 0 "" {TEXT -1 23 "Looking for Periodicity " }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 36 "The c ell below compares the function" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }} {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 259 "" 0 "" {TEXT -1 22 "f(t) = \+ sin(2 Pi 440 t)" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 25 "and the clipped function " }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 257 "" 0 "" {TEXT -1 43 "g(t ) = max(-0.5, min(0.5, sin(2 Pi 440 t)))" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 258 "" 0 "" {TEXT -1 17 "Evaluate it now. " }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 102 "f := \+ t -> sin(2 * Pi * 440 * t):\ng := t -> max(-0.5, min(0.5, f(t))):\n\np lot(\{f(t), g(t)\}, t=0..1/440);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 68 "The following cell illustrates how the Maple integration procedure " }{TEXT 256 4 "int " }{TEXT -1 57 " can be used to work with the exercises in this module. " }{TEXT 257 15 "Evaluate it now" }{TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 0 "" } }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 330 "w := 440:\nf := t -> 3 * \+ sin(2 * Pi * (440 * t + 0.15)):\n\nc := 0:\nd := 1/440:\n\na := (2/(d \+ - c)) * evalf(int(f(t) * cos(2 * Pi * w * t), t = c..d));\nb := (2/(d \+ - c)) * evalf(int(f(t) * sin(2 * Pi * w * t), t = c..d));\nA := sqrt(a ^2 + b^2);\n\ng := t -> a * cos(2 * Pi * w * t) + b * sin(2 * Pi * w * t):\n\nplot(\{f(t), g(t)\}, t = c..d);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 140 "The cell below carries o ut similar computations for a \"clipped\" signal. These computations \+ are numerically difficult. Notice that we use " }{TEXT 258 9 "evalf( Int" }{TEXT -1 28 " with an extra parameter --" }{TEXT 259 2 " 4" } {TEXT -1 47 " -- that indicates we only need a rough answer." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 344 " w := 440:\nf := t -> max(-0.5, min(0.5, sin(2 * Pi * 440 * t))):\n\nc \+ := 0:\nd := 1/440:\n\na := (2/(d - c)) * evalf(Int(f(t) * cos(2 * Pi * w * t), t = c..d, 4));\nb := (2/(d - c)) * evalf(Int(f(t) * sin(2 * P i * w * t), t = c..d, 4));\nA := sqrt(a^2 + b^2);\n\ng := t -> a * cos (2 * Pi * w * t) + b * sin(2 * Pi * w * t):\n\nplot(\{f(t), g(t)\}, t \+ = c..d);" }}}}{MARK "0 2 0" 36 }{VIEWOPTS 1 1 0 1 1 1803 }