convert_plot_spectrum_axis: Convert a weight-based spectrum to a length-based spectrum

In mizer: Dynamic Multi-Species Size Spectrum Modelling

Convert a weight-based spectrum to a length-based spectrum

Description

A density with respect to weight is converted to a density with respect to length with the Jacobian dw/dl = b * w / l. A density with respect to logarithmic weight is instead converted with ⁠d log(w) / d log(l) = b⁠. This is the interface used by the power-based spectrum plots; arrays carry their density measure explicitly and use convert_plot_density_axis() instead.

Usage

convert_plot_spectrum_axis(
  plot_dat,
  params,
  size_axis,
  power,
  per_log_size = power == 2,
  species_col = "Species",
  value_col = 2
)

Arguments

plot_dat	A data frame of plotting data with a w column and a species column.
params	A MizerParams object providing the weight-length parameters.
size_axis	Either "w" (weight) or "l" (length).
power	The power of weight multiplying the number density.
per_log_size	Whether the spectrum is a density with respect to logarithmic size rather than with respect to size. Defaults to power == 2, the only power for which this used to be the case.
species_col	Name of the column identifying the species. Default is "Species".
value_col	Name or index of the value column. Defaults to the second column.

Value

The plotting data with both its size coordinate and spectrum values expressed for the requested axis.

mizer documentation built on Aug. 31, 2026, 5:08 p.m.