It looks like you are attempting to use the function mySMOTE() with your data by putting values into the definition of the function mySMOTE(). You shouldn't do that. Instead, restore the function definition to how it was originally:
function allData_smote = mySMOTE(allData, k,sortedIDX)
And then you can use the function mySMOTE() by calling it with your values as input arguments:
% Note: I'm not sure these are what you intended or whether the function
% mySMOTE() will run with these values, but this is how you call a function
your_allData = [5955,4];
your_k = 5;
your_sortedIdx = {'2552','227','621','2555'};
your_result = mySMOTE(your_allData,your_k,your_sortedIdx);
