How do I change these commands to plot different differential equations?

I have found a video on youtube which does the following code to solve a pair of differential equations:

mu =

300

200

>> eta = [400 100]'

eta =

400

100

>> F=@(t,y) [(1-y(2)/mu(2))*y(1); -(1-y(1)/mu(1))*y(2)]

F =

function_handle with value:

@(t,y)[(1-y(2)/mu(2))*y(1);-(1-y(1)/mu(1))*y(2)]

>> ode45(F,[0 25],eta)

ode45(F,[0 25],eta]

If i have dx/dt = 1.5x - 0.7xy

and dy/dt = 7x - 20.7xy

What should i do to solve these two equations if the initial x and y values are 2.6 and 6 respectively?

Thanks!

I should be getting something similar to this:

[AFHG]

This is the link to the video btw:

https://www.mathworks.com/videos/solving-odes-in-matlab-11-predator-prey-equations-117655.html

Thanks again!

Answer 1

[madhan ravi]

EDITED

mu=[300
   200];
eta = [400 100]';
F=@(t,y) [(1-y(2)/mu(2))*y(1); -(1-y(1)/mu(1))*y(2)]
[t,y]=ode45(F,[0 25],eta)   % you forgot to give outputs
plot(t,y(:,1),'-ob',t,y(:,2),'-or')

[AFHG]

This is done with the values on the video:

I should be getting something like this:

[AFHG]

Also, i think i didnt explain myself correctly, sorry about that.

The y and x both represent different populations.

On the y axes of my graph there should be the population number (so both x and y count as y values basically as they represent the population of two different species) while on the x axis there is time.

[madhan ravi]

"If i have dx/dt = 1.5x - 0.7xy

and dy/dt = 7x - 20.7xy

What should i do to solve these two equations if the initial x and y values are 2.6 and 6 respectively?"

Dont bring up additional questions I solved for the above question!

[AFHG]

I expressed myself wrongly, give me a hand man

Do you know how to do that or?

[madhan ravi]

Can't you solve it in the same way , I showed you? Read the documentation page to get familiar with ode solvers.

[AFHG]

nope, if you see the graph i posted, i should get two different equations

[madhan ravi]

see edited answer

[AFHG]

those are example values in the video, i need different values (shown in the equations i asked), but i dont know how to change it

[madhan ravi]

ah.... which values?? then paramterize your function