I have the following code to plot an approximation using Euler's iteration against the exact value of the function.

I have used x and y for time and population when coding the Euler iterations and t and m for time and population when plotting the exact function. I can't work out how to initialise the m value when plotting the exact function. M(0)=13. When executed the plot looks correct except for that.

"%Compute and Graph Euler's Iteration of dM/dt=-1/40M(M-30) (using x and y)

%Graph Exact Solution of m=30./(1+((17/3)*exp(-3.*t/4)))

clear;

format short;

x=0; %Initialise x value

y=13; %Initialise y value

dx=1; %Step size

n=20; %Number of values to be calculated

for i=1:n

y(i+1)=y(i)+dx.*(-1/40*y(i).*(y(i)-30));

x(i+1)=x(i)+dx;

end

disp(' x y')

disp([x' y'])

t=0:1:20; %Set range of t being alternate units for time in years

m=30./(1+((17/3)*exp(-3.*t/4))); %Population from Exact Function

plot(x,y,t,m)

xlabel('Time in Years');

ylabel('Population')

title('Graph Showing Euler Approximation and Exact Value of Function')"

Wondering if anyone is able to help.

Kind regards

Beetle