seq: Sequence generation along spectra or wavelengths This...

In hyperSpec: Work with Hyperspectral Data, i.e. Spectra + Meta Information (Spatial, Time, Concentration, ...)

Sequence generation along spectra or wavelengths This function generates sequences along the spectra (rows) or wavelengths of hyperSpec objects.

Description

Note that wl2i generates sequences of indices along the wavelength axis.

Usage

## S3 method for class 'hyperSpec'
seq(x, from = 1, to = nrow(x), ..., index = FALSE)

Arguments

x	the hyperSpec object
from, to	arguments handed to seq.int
...	arguments for seq, namely by, length.out
index	should a vector with indices be returned rather than a hyperSpec object?

Details

seq had to be implemented as S3 method as the generic has only ... arguments (on which no dispatch with differing types is possible).

seq_along is not generic, but returns a sequence of the length of the object. As hyperSpec provides a Method length, it can be used. The result is a sequence of indices for the spectra.

Value

a numeric or hyperSpec object, depending on index.

Author(s)

C. Beleites

See Also

wl2i to construct sequences of wavelength indices.

seq

Examples

seq (flu, index = TRUE)
seq_along (flu)
seq (flu, length.out = 3, index = TRUE) # return value is numeric, not integer! 
seq (flu, by = 2, index = TRUE) 		    # return value is numeric, not integer! 

plot (flu, col = "darkgray") 
plot (seq (flu, by = 2), add = TRUE, col= "red")
plot (seq (flu, length.out = 2), add = TRUE, col= "blue")

hyperSpec documentation built on May 29, 2024, 7:28 a.m.