melt_spectra: melt_spectra

In inspectr: Storing, manipulating and analysis spectroscopy and associated data in R.

Description

Melts the spectra data of a Spectra object and returns it as wide format.

Details

This function is very useful when wanting to plot spectra using the lattice or ggplot2 packages.

Methods

x=Spectra

melt_spectra(obj, ...)

	obj	A Spectra object
	...	Ignored

x=SpectraDataFrame

melt_spectra(obj, attr=NULL, ...)

	obj	A SpectraDataFrame object
	attr	Character, the name of an attribute in the object data to split the spectra against.
	...	Ignored

Author(s)

Pierre Roudier [e-mail]

References

Hadley Wickham (2011). The Split-Apply-Combine Strategy for Data Analysis. Journal of Statistical Software, 40(1), 1-29. URL http://www.jstatsoft.org/v40/i01/.

See Also

melt

Examples

# Loading example data
data(australia)
spectra(australia) <- sr_no ~ ... ~ 350:2500

# Simple melt
r <- melt_spectra(australia)
head(r)

## Not run: 
# Melt against some factor (or continuous data), and plot
# using ggplot2

# Create some factor
australia$fact <- sample(LETTERS[1:3], size = nrow(australia), replace = TRUE) # Generate some kind of factor
r <- melt_spectra(australia, attr = 'fact')

# Create plot
library(ggplot2)
p <- ggplot(r) + geom_line(aes(x=wl, y=nir, group=id, colour=fact)) + theme_bw()
print(p)

## End(Not run)

inspectr documentation built on May 2, 2019, 5:45 p.m.