> | #lab3 |
> | with(plots):#plotdisplay(inline); |
> | alpha:=1:lambda:=0.03:beta:=0.4:mu:=0.01: Eq:=[beta/mu,alpha/lambda]:Eqp:=pointplot(Eq,color=red): ODE:=diff(C(t),t)=alpha*C(t)-lambda*C(t)*R(t),diff(R(t),t)=-beta*R(t)+mu*C(t)*R(t); L:=15:c15:=dsolve([ODE,C(0)=L,R(0)=L],numeric,range=0..36,initstep=0.2): |
> | A:=odeplot(c15,[t,C(t)],t=0..36,color=orange): B:=odeplot(c15,[t,R(t)],t=0..36,color=blue): display(A,B); |
> | C15:=odeplot(c15,[C(t),R(t)],t=0..12,color=red): L:=20:c20:=dsolve([ODE,C(0)=L,R(0)=L],numeric,range=0..36,initstep=0.2): L:=25:c25:=dsolve([ODE,C(0)=L,R(0)=L],numeric,range=0..36,initstep=0.2): L:=30:c30:=dsolve([ODE,C(0)=L,R(0)=L],numeric,range=0..36,initstep=0.2): C20:=odeplot(c20,[C(t),R(t)],t=0..12,color=red): C25:=odeplot(c25,[C(t),R(t)],t=0..12,color=red): C30:=odeplot(c30,[C(t),R(t)],t=0..12,color=red): display(C15,C20,C25,C30,Eqp); |
> | beta/mu; |
> | for i from 0 to 36 by 0.2 do c15(i); od; |
> | odeplot(c15,[C(t),R(t)],t=0..36,view=[35..45,10..13]); |
> | alpha:=1.5:beta:=0.4:lambda:=0.03:mu:=0.01:L:=15:Eq2:=[beta/mu,alpha/lambda]: Eq2p:=pointplot(Eq2,color=blue): ODE2:=diff(C(t),t)=alpha*C(t)-lambda*C(t)*R(t),diff(R(t),t)=-beta*R(t)+mu*C(t)*R(t);alpha2:=dsolve([ODE2,C(0)=L,R(0)=L],numeric,range=0..36,initstep=0.2); display(C15,odeplot(alpha2,[C(t),R(t)],t=0..12,color=blue),title="alpha 1.5X carrots multiply faster",Eqp,Eq2p); |
> | alpha:=1:beta:=0.8:lambda:=0.03:mu:=0.01:L:=15:Eq3:=[beta/mu,alpha/lambda]: Eq3p:=pointplot(Eq3,color=blue): ODE3:=diff(C(t),t)=alpha*C(t)-lambda*C(t)*R(t),diff(R(t),t)=-beta*R(t)+mu*C(t)*R(t);beta2:=dsolve([ODE3,C(0)=L,R(0)=L],numeric,range=0..36,initstep=0.2); display(C15,odeplot(beta2,[C(t),R(t)],t=0..12,color=blue),title="beta 2X rabbits leave faster",Eqp,Eq3p ); |
> | alpha:=1:beta:=0.4:lambda:=0.06:mu:=0.01:L:=15:Eq4:=[beta/mu,alpha/lambda]: Eq4p:=pointplot(Eq4,color=blue): ODE4:=diff(C(t),t)=alpha*C(t)-lambda*C(t)*R(t),diff(R(t),t)=-beta*R(t)+mu*C(t)*R(t);lambda2:=dsolve([ODE4,C(0)=L,R(0)=L],numeric,range=0..36,initstep=0.2); display(C15,odeplot(lambda2,[C(t),R(t)],t=0..12,color=blue),title="lambda 2X rabbits eat carrots faster",Eqp,Eq4p); |
> | alpha:=1:beta:=0.4:lambda:=0.03:mu:=0.015:L:=15:Eq5:=[beta/mu,alpha/lambda]: Eq5p:=pointplot(Eq5,color=blue): ODE5:=diff(C(t),t)=alpha*C(t)-lambda*C(t)*R(t),diff(R(t),t)=-beta*R(t)+mu*C(t)*R(t);mu2:=dsolve([ODE5,C(0)=L,R(0)=L],numeric,range=0..36,initstep=0.2); display(C15,odeplot(mu2,[C(t),R(t)],t=0..12,color=blue),title="mu 1.5X carrots have more value to rabbits",Eqp,Eq5p); |
> |