A fast customizable function for locating and measuring the peaks in noisy time-series signals. Adjustable parameters allow discrimination of real signal peaks noise and background. Determines the position, height, and width of each peak by least-squares curve-fitting. It can find and count over 10,000 peaks per second, and find and measure 1800 peaks per second, in very large signals. Includes two interactive versions, one with mouse-controlled sliders and one with keyboard control, for adjusting the peak finding criteria in real-time. Self-contained demos show how it works. See http://terpconnect.umd.edu/~toh/spectrum/PeakFindingandMeasurement.htm for details.-A fast customizable function for locating and measuring the peaks in noisy time-series signals. Adjustable parameters allow discrimination of　real　signal peaks　noise and background. Determines the position, height, and width of each peak by least-squares curve-fitting. It can find and count over 10,000 peaks per second, and find and measure 1800 peaks per second, in very large signals. Includes two interactive versions, one with mouse-controlled sliders and one with keyboard control, for adjusting the peak finding criteria in real-time. Self-contained demos show how it works. See http://terpconnect.umd.edu/~toh/spectrum/PeakFindingandMeasurement.htm for details.