Index in position 1 exceeds array bounds (must not exceed 1) error for a function definition when I run a code in DDE-BIFTOOL

Hi there, I am working in DDEBIFTOOL and I am running a code to plot a bifurctaion diagram. When I hit run in the code, MATLAB gives me the error "Index in position 1 exceeds array bounds (must not exceed 1)" referencing the first line in the funciton defintion (as in bold below):

HollingTanner_rhsSB1c=@(xx,par)[...

(par(1)*xx(2,1)) + (par(1)*xx(2,2)*exp(-par(2)*par(4))) - (par(2)*xx(1,1));....

(par(1)*xx(2,2)*exp(-par(2)*par(4))) - (par(3)*xx(2,1))];

I have done loads of research on this error, but I just cannot see where the problem is in the defintio of this function, given that I have used this code for this funciton in other simulations and it works perfectly.

I am very grateful for any help!

Answer 1

[Sourabh Kondapaka]

Hi,

As you mentioned that the same function was working earlier as intended, I suspect the issue in your current use-case is with the input that is being passed.

It could be that the value that is being passed to the first parameter has only 1 row and inside the function the second row is being accessed, as follows , “xx(2,1)”

Below code is a much a simpler example which throws the same error as yours.

%% Has 1 row and 2 columns.
a = zeros(1,2);

%% Accessing the second row first index which is out of bounds.
disp(a(2,1));

Hence throws a similar error to yours:

Index in position 1 exceeds array bounds (must not exceed 1)