Plot abundance and biomass spectra

plotSpectra() plots either a number density or a biomass density, either with respect to size or with respect to logarithmic size. Those two choices are made with the biomass and per_log_size arguments. When called with a MizerSim object, the abundance is averaged over the specified time range (a single value for the time range can be used to plot a single time step). When called with a MizerParams object the initial abundance is plotted. With size_axis = "l", densities are converted from per unit weight to per unit length; densities with respect to logarithmic size are instead converted between logarithmic weight and logarithmic length intervals.

Usage

plotSpectra(
  object,
  species = NULL,
  wlim = c(NA, NA),
  llim = c(NA, NA),
  ylim = c(NA, NA),
  power = NULL,
  biomass = NULL,
  per_log_size = NULL,
  total = FALSE,
  resource = TRUE,
  background = TRUE,
  highlight = NULL,
  log_x = TRUE,
  log_y = TRUE,
  log = NULL,
  size_axis = c("w", "l"),
  return_data = FALSE,
  ...
)

Arguments

object

An object of class MizerSim or MizerParams.

species

The species to be selected. Optional. By default all target 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.

wlim

A numeric vector of length two providing lower and upper limits for the w axis. Use NA for the default: the lower default is min(params@w) / 100 when resource = TRUE (to show some resource below the fish grid) or min(params@w) when resource = FALSE; the upper default is max(params@w_full). Data is filtered to this range and the axis limits are set accordingly.

llim

A numeric vector of length two providing lower and upper limits for the length axis when size_axis = "l". Use NA to auto-scale to the data range. Data is filtered to this range and the axis limits are set accordingly.

ylim

A numeric vector of length two providing lower and upper limits for the y axis. Use NA to auto-scale to the data range. Values below 1e-20 are always filtered out from the data regardless of ylim[1]. Data above ylim[2] is filtered and the upper axis limit is set accordingly.

power

The abundance is plotted as the number density times the weight raised to power. An alternative to the biomass and per_log_size arguments, with which it must agree if they are given as well; see Details. The default is power = 1, the biomass density.

biomass

Whether to plot the biomass density (TRUE, the default) or the number density (FALSE).

per_log_size

Whether to plot the density with respect to logarithmic size (TRUE) or with respect to size (FALSE, the default).

total

A boolean value that determines whether the total is plotted as well. The total is the total of everything the object holds — every species and the resource — whatever is drawn, so it does not move when species, resource or background change. Default is FALSE.

resource

A boolean value that determines whether resource is included. Default is TRUE.

background

A boolean value that determines whether background species are included. Ignored if the model does not contain background species. Default is TRUE.

highlight

Name or vector of names of the species to be highlighted by being plotted with thicker lines.

log_x

If TRUE (default), use a log10 x-axis.

log_y

If TRUE (default), use a log10 y-axis.

log

Character string specifying which axes should use log10 scales, in the same form as the base plot() argument. For example, "x", "y", "xy" or "". If supplied, this overrides log_x and log_y.

size_axis

Whether to plot size as weight ("w", default) or length ("l"), using the allometric weight-length relationship. Spectrum densities and their units are transformed to match the chosen axis.

return_data

A boolean value that determines whether the formatted data used for the plot is returned instead of the plot itself. Default value is FALSE

...

Further arguments used by only some of the methods:

For MizerSim methods:

time_range: The time range (either a vector of values, a vector of min and max time, or a single value) to average the abundances over. Default is the final time step.
geometric_mean: If TRUE then the average of the abundances over the time range is a geometric mean instead of the default arithmetic mean.

Value

A ggplot2 object, unless return_data = TRUE, in which case a data frame with the four variables 'w' (or 'l' if size_axis = "l"), 'value', 'Species', 'Legend' is returned. plotlySpectra() returns a plotly object.

Details

The plotted quantity is the number density multiplied by w^power, where the power is the sum of the two choices above: a biomass density carries one factor of the weight and a density with respect to logarithmic size carries another:

	`per_log_size = FALSE`	`per_log_size = TRUE`
`biomass = FALSE`	`power = 0`	`power = 1`
`biomass = TRUE`	`power = 1`	`power = 2`

The power argument can still be given instead, and is the only way to ask for a power that is not the sum of the two flags. But note that power on its own does not distinguish the two entries with power = 1: it is taken to mean the biomass density with respect to weight, which is what determines the y-axis label and the Jacobian used for a length axis. Supplying power together with a flag that contradicts it is an error.

The log_x argument only controls how the size axis is displayed; it does not change the density on the y-axis. In particular, showing weight on a logarithmic axis does not by itself convert a density per unit weight into a density per logarithmic weight interval. That choice is made with per_log_size, and the conversion from weight to length then uses the logarithmic Jacobian, irrespective of the value of log_x.

plotlySpectra() is the interactive plotly version. To compare spectra from two objects use plotSpectra2(). To show relative differences use plotSpectraRelative().

Examples

# \donttest{
params <-  NS_params
sim <- project(params, effort=1, t_max=20, t_save = 2, progress_bar = FALSE)
#> ℹ No `a` column so using a = 0.01 in w = a l^b, with w in g and l in cm.
#> ℹ No `b` column so using the isometric default b = 3 in w = a l^b.
plotSpectra(sim)

plotSpectra(sim, wlim = c(1e-6, NA))

plotSpectra(sim, time_range = 10:20)

plotSpectra(sim, time_range = 10:20, biomass = FALSE)

plotSpectra(sim, species = c("Cod", "Herring"), per_log_size = TRUE)

plotSpectra(sim, species = c("Cod", "Herring"), size_axis = "l")


# Returning the data frame
fr <- plotSpectra(sim, return_data = TRUE)
str(fr)
#> 'data.frame':	1024 obs. of  4 variables:
#>  $ w              : num  0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 ...
#>  $ Biomass density: num  1.83e+10 6.92e+09 1.30e+11 1.46e+10 1.69e+08 ...
#>  $ Species        : chr  "Sprat" "Sandeel" "N.pout" "Herring" ...
#>  $ Legend         : chr  "Sprat" "Sandeel" "N.pout" "Herring" ...
# }

Usage

Arguments

Value

Details

See also

Examples