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Newbie: How to write Xn+1 = functions? Follow 49 views (last 30 days) Show older comments Vic Zommer on 15 Jun 2016

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Answered: John D'Errico on 15 Jun 2016 Accepted Answer: John D'Errico Hi!! Can somebody be so nice to show me an example how to plot this function into Matlab or just Manuals/Beginners Guide where I can find help on Xn+1 functions. Sorry :( Xn+1 = An*XnAn={A0 if n is even; A1 if n is odd;X0>0A1, A2 > 0Or if it is easier for you: Xn+1=r*Xn/1+XnX-1, X0 > 0r>0

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John D'Errico on 15 Jun 2016

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Open in MATLAB Online I'd normally not answer a basic question. But you did show some thought.A loop is simplest. Yes, there are lots of ways you could do this in a more sophisticated way. But a loop is a good way to start for something simple.% picking some simple values for N, A0, A1N = 100;A0 = 1.5;A1 = 0.75;% Preallocate X to be the right size. DO THIS FOR VECTORS% that will grow in size. If not you will be unhappy one day!!!!!!!!X = zeros(1,N);% I'll assume the first element is A1X(1) = A1;for n = 1:(N-1)if rem(n,2) == 0% even case An = A0;else% odd case An = A1;end% step to increment X(n) to X(n+1) X(n+1) = An*X(n)endBe careful. You cannot have an X(0) element. MATLAB indexing is 1 based.Ok, so, COULD we have done this in a vectorized way? Of course. In fact, that is what you should strive for as you grow in ability.N = 100;A0 = 1.5;A1 = 0.75;A = [A1,A0];X = cumprod(A(rem(1:N,2) + 1));Faster to write the second way, and I'll bet it is faster to execute.

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