I have row vectors representing the appearance of a stimulus. The stimuli are logged as a square wave such that when the stimulus is present the vector elements change values until it disappears. I also have a time vector with the same number of elements. I would like to change the stimulus vector into a vector of 1s and 0s such that there is a 1 for the time the stimulus is present, and zero otherwise. If possible I'd like to index it to the time vector so that I have the time the stimulus is present. Of course, there may be a better way to achieve the goal. Please help. I've spent so many hours on such a simple problem! Thank you!