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Plot the relative difference or percent change between two spectra

plotSpectraRelative.Rd

This plots a measure of the relative difference between the steady state spectra of two mizer objects. The user can choose how this difference is calculated. Let the spectra of the two objects be represented as \(N_1(w)\) and \(N_2(w)\).

Usage

plotSpectraRelative(
  object1,
  object2,
  species = NULL,
  power,
  diff_method = "percent_change",
  ...
)

plotlySpectraRelative(object1, object2, diff_method, ...)

Arguments

object1

An object of class MizerSim or MizerParams

object2

An object of class MizerSim or MizerParams

species

The species to be selected. Optional. By default all species are selected. A vector of species names, or a numeric vector with the species indices, or a logical vector indicating for each species whether it is to be selected (TRUE) or not.

power

The abundance is plotted as the number density times the weight raised to this power. The default power = 1 gives the biomass density, whereas power = 2 gives the biomass density with respect to logarithmic size bins.

diff_method

The method to calculate the relative change between models. If percent.change, the percent change is calculated relative to the value from object 1 with formula 100*(new-old)/old. If rel.diff the relative difference is returned given by (new - old)/(old + new).

...

Parameters passed to plotSpectra()

Value

A ggplot2 object

Details

If diff_method is given as percent_change, this function plots the percent change, given by $$ 100*(N_2(w) - N_1(w)) / (N_1(w)).$$

If diff_method is given as rel_diff the difference is calculated relative to their average, so $$2 (N_2(w) - N_1(w)) / (N_2(w) + N_1(w)).$$

The individual spectra are calculated by the plotSpectra() function which is passed all additional arguments you supply. So you can for example determine a size range over which to average the simulation results via the time_range argument. See plotSpectra() for more options.

Note that it does not matter whether the relative difference is calculated for the number density or the biomass density or the biomass density in log weight because the factors of \(w\) by which the densities differ cancels out in the relative difference.

See also

Other plotting functions: plot2Productivity(), plot2TotalBiomass(), plotBiomass(), plotProductivity(), plotProductivityRelative(), plotRefuge(), plotRelativeContribution(), plotTotalAbundance(), plotTotalBiomass(), plotTotalBiomassRelative(), plotVulnerable()