{VERSION 2 3 "SUN SPARC SOLARIS" "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 } {PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "Helvetica" 1 12 0 0 0 0 1 2 2 0 0 0 0 0 0 }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 } 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 14 0 0 0 0 2 2 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" -1 258 1 {CSTYLE "" -1 -1 "Courier" 1 12 0 0 0 0 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 3" -1 259 1 {CSTYLE "" -1 -1 "Courier" 1 12 0 0 0 0 2 2 2 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "R3 Font 4 " -1 260 1 {CSTYLE "" -1 -1 "Courier" 1 12 0 0 0 0 2 2 2 0 0 0 0 0 0 } 0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "R3 Font 5" -1 261 1 {CSTYLE "" -1 -1 "Helvetica" 1 12 0 0 0 0 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 6" -1 262 1 {CSTYLE "" -1 -1 "Helveti ca" 1 12 0 0 0 0 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 7" -1 263 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 0 2 2 2 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "R3 Font 8" -1 264 1 {CSTYLE "" -1 -1 "Helvetica" 1 12 0 0 0 0 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 9" -1 265 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 0 2 2 2 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "R3 Font 10" -1 266 1 {CSTYLE "" -1 -1 "Helvetica " 1 12 0 0 0 0 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 11" -1 267 1 {CSTYLE "" -1 -1 "Helvetica" 1 12 0 0 0 0 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 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 " " 0 "" {TEXT 256 11 "test.mws " }{TEXT -1 21 " Predator-prey models " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 37 "restart: with(DEtools): with(linalg):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 59 "eq1:=diff ( V(t), t) = a* V *(1 -(V/ K)) - b* H * V /(V+ e);" }}{PARA 0 "> " 0 " " {MPLTEXT 1 0 44 "eq2:=diff( H(t), t) = c * V *H/(e+V) -d* H ;" }} {PARA 0 "> " 0 "" {MPLTEXT 1 0 20 "vars:= [V(t), H(t)];" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 44 "equil:= solve( \{rhs(eq1), rhs(eq2) \}, \{V,H\});" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 94 "\nHere is the al ternate method for computing the coefficient matrix using the jacobian command." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 86 "J:= jacobian([rhs(eq1) ,rhs(eq2)], [V,H]); # computes the partials and forms the matrix" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 100 "A:= subs(\{V = d*e/(c-d), H = -a*e*c*(K*d-K*c+d*e)/b/K/(c^2-2*c*d+d^2)\}, evalm(J)); # same as b efore" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 41 "B:= eigenvals(A); \+ h:=solve(rhs(eq1), H);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 48 " params:=a=0.5, b=.001, c=.5, d=.4, K=500, e=100;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 27 "subs(params, \{B[1], B[2]\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 29 "bar:= subs(params, equil[3]);" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 19 "Vbar:=subs(bar, V);" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 89 "P1:= plot(subs(params,h), V= 0..500, thickness=3,color=black, axesfont=[COURIER,BOLD,12]):" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 62 "P2:= plot([[Vbar,0], [Vbar, \+ 90000]], style=line, thickness=3):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 24 "plots[display](\{P1,P2\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 47 "para ms:=a=0.5, b=.001, c=.5, d=.4, K=500, e=25;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 27 "subs(params, \{B[1], B[2]\});" }}}{EXCHG {PARA 0 " > " 0 "" {MPLTEXT 1 0 29 "bar:= subs(params, equil[3]);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 19 "Vbar:=subs(bar, V);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 89 "P1:= plot(subs(params,h), V=0..500, thickness=3,color=black, axesfont=[COURIER,BOLD,12]):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 62 "P2:= plot([[Vbar,0], [Vbar, 75000]] , style=line, thickness=3):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 24 "plots[display](\{P1,P2\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{PARA 0 "" 0 "" {TEXT -1 1 "\n" }}}{MARK "24 0" 1 } {VIEWOPTS 1 1 0 1 1 1803 }