peaks -- find the peaks in an array of x and y points
npeaks = peaks (x, y, background, npts, dx) real x[npts], y[npts] # Input data points and output peaks real background[npts] # Background estimate int npts # Number of input data points real dx # Precision of peak positions
The extrema in the input data points are found using extrema(xtools). The extrema are located to a precision of dx. The extrema with negative curvature (peaks) are selected and returned in the x array. The spline value is returned in the y array. The background is estimated by linear interpolation of the neighboring minima (extrema of positive curvature) to the position of the peak. The background is returned in the background array. The number of peaks found is returned as the function value.