PeakPosition

PeakPosition is a term used in signal processing and analytical chemistry to denote the estimated coordinate of a peak in a data series or image. It refers to the value of the independent variable at which the signal attains its maximum (or a local maximum in the presence of multiple peaks), expressed as time, wavelength, pixel position, or spatial coordinate, depending on the data.

The initial estimate is usually found by identifying the sample with the maximum intensity within a defined window. Refinement methods include interpolating between samples with a parabolic fit around the peak or fitting a small model, such as Gaussian or Lorentzian, to surrounding points to achieve sub-sample accuracy. In multidimensional data, peak position can be refined by computing the centroid (center of mass) of a peak region or by two- or three-dimensional model fitting.

PeakPosition is sensitive to noise, baseline drift, and peak overlap. Preprocessing steps such as smoothing, background subtraction, and deconvolution or deblending of overlapping peaks improve accuracy. The choice of window size, smoothing strength, and the model used for refinement influence bias and variance in the resulting position estimate.

Applications are widespread and include spectroscopy, chromatography, mass spectrometry, imaging, and time-resolved measurements. Related concepts include peak centroid, peak picking, apex detection, and peak localization. The method chosen for PeakPosition often depends on data quality, peak shape, and the desired sub-sample accuracy.

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