{VERSION 5 0 "IBM INTEL NT" "5.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 1 }{CSTYLE "2D Math" -1 2 "Times" 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 1 }{CSTYLE "2D Comment" 2 18 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "2D Output" 2 20 "" 0 1 0 0 255 1 0 0 0 0 0 0 0 0 0 1 } {PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }1 1 0 0 0 0 1 0 1 0 2 2 0 1 }{PSTYLE "Maple Output" -1 11 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }3 3 0 0 0 0 1 0 1 0 2 2 0 1 }} {SECT 0 {EXCHG {PARA 0 "" 0 "" {TEXT -1 95 "This Maple Procedure imple ments the Euler Approximation to a differential equation of the type \+ " }{XPPEDIT 18 0 "dx/dt = f(t,x);" "6#/*&%#dxG\"\"\"%#dtG!\"\"-%\"fG6$ %\"tG%\"xG" }{TEXT -1 171 ", where f is a vector-valued function and x is a vector. Furthermore, the differential equation is linear in ter ms of the vector x, that is, it is a First-Order equation." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 664 "with(linalg):\nRKSys:= proc(f,tsta rt, xstart, tend, n)\nlocal h, i, k, t, x, k1, k2, k3, k4;\nh := evalf ((tend - tstart)/n);\nt:=tstart: x:=xstart:\nprint('Step','t','x'); \nfor i from 1 to n+1 do\n print(i-1,t,x); # displa y current values\n k1 := f(t,x): \011\011\011 # the l eft-hand slope\n\011 k2 := f(t+h/2,evalm(x+h*k1/2)):\011 # 1st midpoi nt slope\n\011 k3 := f(t+h/2,evalm(x+h*k2/2)):\011 # 2nd midpoint slo pe\n\011 k4 := f(t+h,evalm(x+h*k3)): \011\011 # the right-hand slop e\n k := evalm((k1+2*k2+2*k3+k4)/6):\011# the average slope\n\011 x := evalm(x + h*k): \011\011 # R-K step to update x\n\011 t \+ := t + h: \011\011 # update t\nod:\nprint(f);\nend: " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 103 "The Syntax is as follows: RK Sys(function, initial t, initial-value vector x, final t, number of st eps);" }}{PARA 0 "" 0 "" {TEXT -1 16 "Examples follow:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 77 "f:=(t,x) -> evalm(<<2,3,3>|<3,4,3>| <1,0,0>> &* x + <>);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%\"fGf*6$%\"tG%\"xG6\"6$%)operatorG%&arrowGF)-%&evalmG 6#,&-%#&*G6$-%$<|gr>G6%-%$<,>G6%\"\"#\"\"$F;-F86%F;\"\"%F;-F86%\"\"\" \"\"!FB9%FA-F86#-F86%-%$sinG6#9$-%$cosGFJ-%$tanGFJFAF)F)F)" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 26 "RKSys(f,0,<<1,1,0>>,1,10);" }} {PARA 11 "" 1 "" {XPPMATH 20 "6%%%StepG%\"tG%\"xG" }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"!F#-%'RTABLEG6%\")GMo@-%'MATRIXG6#7%7#\"\"\"F,7#F#% 'MatrixG" }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"\"$\"+++++5!#5-%'matri xG6#7%7#$\"+IO*fv\"!\"*7#$\"+\"4=^4#F.7#$\"+*\\%o6&)F&" }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"#$\"+++++?!#5-%'matrixG6#7%7#$\"+Hj?>L!\"*7#$ \"+50mGTF.7#$\"+.\"p1]#F." }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"$$\"+ ++++I!#5-%'matrixG6#7%7#$\"+_$)fEk!\"*7#$\"+x#o+(zF.7#$\"+r(\\no&F." } }{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"%$\"+++++S!#5-%'matrixG6#7%7#$\"+ 32Z\\7!\")7#$\"+fV4H:F.7#$\"+QKu#=\"F." }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"&$\"+++++]!#5-%'matrixG6#7%7#$\"+YskCC!\")7#$\"+tr\\IHF.7#$ \"+&[OZO#F." }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"'$\"+++++g!#5-%'mat rixG6#7%7#$\"+m@i\"p%!\")7#$\"+()H.>cF.7#$\"+lgGQYF." }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"($\"+++++q!#5-%'matrixG6#7%7#$\"+S)3m0*!\")7#$\" +')3Cy5!\"(7#$\"+:<%)4!*F." }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\")$\" +++++!)!#5-%'matrixG6#7%7#$\"+\"=!RXgL!\"(7#$\"+lDFxRF.7#$\"+i8&pN$F." }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"#5$\"+++++5!\"*-%'matrixG6#7%7#$\"+o]([Y'!\"(7#$\"+]d oUwF.7#$\"+Gh]ikF." }}{PARA 11 "" 1 "" {XPPMATH 20 "6#f*6$%\"tG%\"xG6 \"6$%)operatorG%&arrowGF'-%&evalmG6#,&-%#&*G6$-%$<|gr>G6%-%$<,>G6%\"\" #\"\"$F9-F66%F9\"\"%F9-F66%\"\"\"\"\"!F@9%F?-F66#-F66%-%$sinG6#9$-%$co sGFH-%$tanGFHF?F'F'F'" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 51 "g: = (t,x) -> evalm(<|> &* x);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%\"gGf*6$%\"tG%\"xG6\"6$%)operatorG%&arrowGF)-%&evalmG 6#-%#&*G6$-%$<|gr>G6$-%$<,>G6$9$*$)F9\"\"#\"\"\"-F76$-%$expG6#F9-%$sin GFB9%F)F)F)" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 23 "RKSys(g,0,<< 1,1>>,1,5);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6%%%StepG%\"tG%\"xG" }} {PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"!F#-%'RTABLEG6%\")/7@@-%'MATRIXG6# 7$7#\"\"\"F,%'MatrixG" }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"\"$\"++++ +?!#5-%'matrixG6#7$7#$\"+L*[iC\"!\"*7#$\"+vzHB5F." }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"#$\"+++++S!#5-%'matrixG6#7$7#$\"+e*4+i\"!\"*7#$\"+M YW86F." }}{PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"$$\"+++++g!#5-%'matrixG6 #7$7#$\"+1\\q5A!\"*7#$\"+,$\\tK\"F." }}{PARA 11 "" 1 "" {XPPMATH 20 "6 %\"\"%$\"+++++!)!#5-%'matrixG6#7$7#$\"+(Gar?$!\"*7#$\"+xPq#z\"F." }} {PARA 11 "" 1 "" {XPPMATH 20 "6%\"\"&$\"+++++5!\"*-%'matrixG6#7$7#$\"+ =SbY]F&7#$\"+ph\"*4GF&" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#f*6$%\"tG%\" xG6\"6$%)operatorG%&arrowGF'-%&evalmG6#-%#&*G6$-%$<|gr>G6$-%$<,>G6$9$* $)F7\"\"#\"\"\"-F56$-%$expG6#F7-%$sinGF@9%F'F'F'" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}}{MARK "1 0 0" 13 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }{RTABLE_HANDLES 21683428 21211204 }{RTABLE M7R0 I5RTABLE_SAVE/21683428X,%)anythingG6"6"[gl!"%!!!#$"$"""""F'""!F& } {RTABLE M7R0 I5RTABLE_SAVE/21211204X,%)anythingG6"6"[gl!"%!!!##"#"""""F'F& }