photobiology (version 0.9.6)

get_peaks: Get peaks and valleys in a spectrum

Description

These functions find peaks (local maxima) or valleys (local minima) in a spectrum, using a user selectable size threshold relative to the tallest peak (global maximum). This a wrapper built on top of function peaks from package splus2R.

Usage

get_peaks(x, y, ignore_threshold = 0, span = 5, strict = TRUE,
  x_unit = "", x_digits = 3)

get_valleys(x, y, ignore_threshold = 0, span = 5, strict = TRUE,
  x_unit = "", x_digits = 3)

Arguments

x

numeric

y

numeric

ignore_threshold

numeric Value between 0.0 and 1.0 indicating the relative size compared to tallest peak or deepest valley of the peaks to return.

span

numeric A peak is defined as an element in a sequence which is greater than all other elements within a window of width span centered at that element. For example, a value of 3 means that a peak is bigger than both of its neighbors.

strict

logical Flag: if TRUE, an element must be strictly greater than all other values in its window to be considered a peak. Default: TRUE.

x_unit

character Vector of texts to be pasted at end of labels built from x value at peaks.

x_digits

numeric Number of significant digits in wavelength label.

Value

• A data frame with variables w.length and s.irrad with their values at the peaks or valleys plus a character variable of labels.

See Also

Other peaks and valleys functions: find_peaks, peaks, valleys

Examples

with(sun.spct, get_peaks(w.length, s.e.irrad))
with(sun.spct, get_valleys(w.length, s.e.irrad))