{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 }{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 }} {SECT 0 {EXCHG {PARA 0 "" 0 "" {TEXT -1 61 "Solve ordinary differentia l equation: (initial value problem)" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 49 "eq:=diff(u(x),x,x)+2*u(x)=0; dsolve(\{eq\},\{u(x)\}); " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 49 "ini:= u(0)=5, D(u)(0)=1 ; dsolve(\{eq,ini\},\{u(x)\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 43 "sol:=dsolve(\{eq,ini\},\{u(x)\}, type=numeric);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 15 "sol(1); sol(2);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 27 "odeplot(sol,[x,u(x)],0..5);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 33 "How about boundary value problem?" }} {PARA 0 "> " 0 "" {MPLTEXT 1 0 67 "eq1:=diff(u(x),x,x)+2*u(x)=0; gener al_solution:=dsolve(\{eq1\},u(x));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 35 "dsolve(\{eq1,u(0)=2,u(1)=3\},\{u(x)\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 11 "u1:=rhs(%);" }}}{EXCHG }{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 16 "plot(u1,x=0..5);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 44 "Now let's solve some PDE: diffusion equation" } }{PARA 0 "> " 0 "" {MPLTEXT 1 0 61 "with(PDEtools): diffusion:=diff(u( t,x),t)=2*diff(u(t,x),x,x);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 43 "pdsolve(diffusion, u(t,x), HINT=X(x)*T(t));" }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 52 "pdsolve(diffusion, u(t,x), HINT=X(x)*T(t), 'bu ild');" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }{TEXT -1 31 "Here is \+ the numerical solution:" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 44 "IBC:=\{u (0,x)=sin(Pi*x), u(t,0)=0, u(t,1)=0\};" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 54 "pds:=pdsolve(diffusion, IBC, numeric, spacestep=1/40) ;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 31 "pds:-animate(t=0.2,fra mes=100);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}}{MARK "8 0 0" 11 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }