源程序代码及图像.doc

function xdot=shier(t,x)r=1;N=10;xdot=r*x.*(1-x/N); plot(t,x),grid,gtext(x(t), ts=0:0.1:9; x0=1; t,x=ode45(shier,ts,x0);t,x,ans = 0 1 0.1 1.09366870402699 0.2 1.19494494403897 0.3 1.30422936541302 0.4 1.42189648248146 0.5 1.54828572709947 0.6 1.68370144864509 0.7 1.82837907769168 0.8 1.98252270576385 0.9 2.14627778425928 1 2.31967566117649 1.1 2.50263358111483 1.2 2.69495468527452 1.3 2.89632801145658 1.4 3.10632849406291 1.5 3.32441696409622 1.6 3.54997350135924 1.7 3.78217560297504 1.8 4.02005386393033 1.9 4.26258449994887 2 4.50868934749154 2.1 4.75723586375631 2.2 5.00703712667823 2.3 5.25685183492947 2.4 5.50538430791926 2.5 5.75139615567981 2.6 5.99373859277315 2.7 6.23129495456666 2.8 6.4630624345751 2.9 6.68815208446065 3 6.90578881403287 3.1 7.11531139124876 3.2 7.31617244221268 3.3 7.50793845117643 3.4 7.69031194827925 3.5 7.86315346742664 3.6 8.02640815758842 3.7 8.18009618834515 3.8 8.32431274988817 3.9 8.45922805301956 4 8.58508732915215 4.1 8.70221083030955 4.2 8.81099382912612 4.3 8.91186250439345 4.4 9.005188861967 4.5 9.09134929987153 4.6 9.17072837524719 4.7 9.24371880434953 4.8 9.31072146254947 4.9 9.37214538433334 5 9.42840776330284 5.1 9.47993395217508 5.2 9.52711886139905 5.3 9.57025879291524 5.4 9.60963337116114 5.5 9.64551697410302 5.6 9.6781787332359 5.7 9.70788253358356 5.8 9.73488701369858 5.9 9.75944556566228 6 9.78180633508476 6.1 9.80217976640637 6.2 9.82070899245758 6.3 9.83753443714193 6.4 9.85279276511187 6.5 9.86661688176873 6.6 9.87913593326272 6.7 9.89047530649299 6.8 9.90075662910753 6.9 9.91009776950327 7 9.91859304724388 7.1 9.92630227788946 7.2 9.93328741184239 7.3 9.93960860943719 7.4 9.9453242409406 7.5 9.95049088655155 7.6 9.95516333640114 7.7 9.95939459055266 7.8 9.96323585900161 7.9 9.96672693648818 8 9.96989210939346 8.1 9.97275740536695 8.2 9.97534808238276 8.3 9.97768862873969 8.4 9.97980276306117 8.5 9.98171343429529 8.6 9.98344282171477 8.7 9.98501233491702 8.8 9.98643668704328 8.9 9.98772581879707 9 9.98889254632246 plot(t,x),grid,gtext(x(t), xlabel(T)ylabel(N(t) pausefunction l=logistic(t,x)r=1 1;n=100 100;m=1.5 0.7;l=r(1)*x(1)*(1-x(1)/n(1)+m(1)/n(2);r(2)*x(2)*(1-x(2)/n(2)+m(2)/n(1); x0=10 10; t0=0 10; t,x=ode45(logistic,t0,x0); plot(t,x(:,1),r,t,x(:,2),b);xlabel(时间);ylabel(种群数量); title(种群数量与时间的关系); text(t(16),x(16,1),leftarrow种群一的数量); text(t(18),x(18,2),种群二的数rightarrow,HorizontalAlignment,right); pausefunction l=logistic(t,x)r=1 0.5;n=100 100;m=1.5 0.7;l=r(1)*x(1)*(1-x(1)/n(1)+m(1)/n(2);r(2)*x(2)*(1-x(2)/n(2)+m(2)/n(1); x0=10 10; t0=0 10; t,x=ode45(logistic,t0,x0); plot(t,x(:,1),r,t,x(:,2),b);xlabel(时间);ylabel(种群数量); title(种群数量与时间的关系); text(t(16),x(16,1),leftarrow种群一的数量); text(t(18),x(18,2),种群二的数rightarrow,HorizontalAlignment,right); pausefunction l=logistic(t,x)r=0.5 1;n=100 100;m=1.5 0.7;l=r(1)*x(1)*(1-x(1)/n(1)+m(1)/n(2);r(2)*x(2)*(1-x(2)/n(2)+m(2)/n(1); x0=10 10; t0=0 10; t,x=ode45(logistic,t0,x0); plot(t,x(:,1),r,t,x(:,2),b);xlabel(时间);ylabel(种群数量); title(种群数量与时间的关系); text(t(16),x(16,1),leftarrow种群一的数量); text(t(18),x(18,2),种群二的数rightarrow,HorizontalAlignment,right); pausefunction l=logistic(t,x)r=1 1;n=100 50;m=1.5 0.7;l=r(1)*x(1)*(1-x(1)/n(1)+m(1)/n(2);r(2)*x(2)*(1-x(2)/n(2)+m(2)/n(1); x0=10 10; t0=0 10; t,x=ode45(logistic,t0,x0); plot(t,x(:,1),r,t,x(:,2),b);xlabel(时间);ylabel(种群数量); title(种群数量与时间的关系); text(t(16),x(16,1),leftarrow种群一的数量); text(t(18),x(18,2),种群二的数rightarrow,HorizontalAlignment,right); pausefunction l=logistic(t,x)r=1 1;n=50 100;m=1.5 0.7;l=r(1)*x(1)*(1-x(1)/n(1)+m(1)/n(2);r(2)*x(2)*(1-x(2)/n(2)+m(2)/n(1); x0=10 10; t0=0 10; t,x=ode45(logist