I suspect the problem Rita and Michael were having is that their data describes a decreasing logistic and the program is set up to do an increasing logistic. I just uploaded a non-GUI fit_logistic function and at first it failed with Rita's data, too. Fortunately, it is an easy fix by making the time series negative.
hi Varuna De Silva,
This is the errors I received while following your instructions on the readme.txt
??? Attempt to reference field of non-structure array.
Error in ==> Logistic>plotBut_Callback at 159
Error in ==> gui_mainfcn at 96
Error in ==> Logistic at 30
??? Error while evaluating uicontrol Callback