{VERSION 5 0 "IBM INTEL LINUX" "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 "" -1 256 "times" 1 18 0 0 0 0 0 0 0 0 0 0 0 0 0 0 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 0 2 2 2 0 0 0 0 0 0 1 }0 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 0 0 0 0 2 1 2 0 0 0 0 0 0 1 }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 24 0 0 0 0 2 2 2 0 0 0 0 0 0 1 }0 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 0 0 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 258 "" 0 "" {TEXT 256 35 "Phase Portrait for a Li enard System" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 36 "restart:\nw ith(plots):\nwith(DEtools):" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 50 "De fine the differential equation using parameters:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 83 "LienardDE := [diff(x(t),t) = y(t),\n \+ diff(y(t),t) = (1-x(t)^4)*y(t)-x(t)];" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 120 "Plot the phaseportrait using Runge-Kutta method; the in itial conditions are given in the first line and can be changed." }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 44 "IC:=[[x(0)= 0,y(0)=1.5],[x(0 )= 0,y(0)=2.3]];" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 159 "DEplot(Lienard DE, [x(t),y(t)], t=0..10, \n IC,linecolour=BLUE, x=-3..3, y=-3..3, s tepsize=0.05,\n arrows=NONE, method=classical[rk4], title=`Lienard Sy stem`);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 80 "You could try changing the parameters in \+ the equation to get different examles. " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 15 "Plot x versus t" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 209 "ICt:=[[x(0)= 0,y(0)= 1.5]];\nDEplot(LienardDE, [x(t),y(t)], t=0..20, \n ICt,linecolour=BL UE, x=-3..3, y=-4..4, stepsize=0.05,\n arrows=NONE, method=classical[ rk4],scene=[t,y], \n title=`Lienard System: (t,y)`);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 58 "Plot the vector field for x' = x(2-x-y) , y' = y(3-x-2y)" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 57 "fieldp lot([y,(1-x(t)^4)*y(t)-x(t)], x = -3..3, y=-3..3);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}}{MARK "1 0 0" 9 }{VIEWOPTS 1 1 0 3 2 1804 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }