Hi! I have an array that is 1 column by many rows, of which each element represents a time. I want to find variable f at each time, where f is defined as follows: if t < tp f=(sin((pi*t)/(2*tp)))^2; if tp < t < ts f=(cos((pi*(t-tp))/(2*(ts-tp))))^2; otherwise f=0 I've tried defining f as above in a .m function file (called elastance), and then using f=arrayfun(elastance,t) to find f at each time, but that doesn't work (It says, "Error in ==> elastance at 5, if t < tp".) Just typing the above function directly into the command window doesn't work either, whether or not I put it in terms of t or (t.). Does anyone have any suggestions? Thanks!