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`plot` plot the two-dimensional chromatogram as a contour plot.


plot(Object, type = "f", ...)

# S4 method for GCxGC
plot(Object, type = "f", ...)



a GCxGC chromatogram, it can be a raw, or preprocessed chromatogram.


a character indicating the type of chromatogram representation. By default, type = "f" for filled.contour function, if type = "c" only contours or isolines will be displayed by using the contour function.


Other parameters passed to filled.contour or filled.contour function, it depends on the value of the type argument.


This plot function employs the built-in contour function. As mentioned in Reichenbach et al. (2004) , interpolation is used to display non-native GCxGC data.


Reichenbach SE, Ni M, Kottapalli V, Visvanathan A (2004). “Information technologies for comprehensive two-dimensional gas chromatography.” Chemometrics and Intelligent Laboratory Systems, 71(2), 107--120.


chrom_name <-  system.file("extdata", "08GB.cdf", package = "RGCxGC")
chrom_2D <- read_chrom(chrom_name, 5L)
#> Warning: The last 51 signals will be omitted
#> Warning: data length [61051] is not a sub-multiple or multiple of the number of rows [500]
#> Retention time ranges:
#> 1D (min): 7.98 18.16 
#> 2D (sec): 0 5 
#> Acquisition rate: 100 
plot(chrom_2D, nlevels = 150, color.palette =

plot(chrom_2D, type = "c", nlevels = 50, col =