plot.dfunc.para: plot.dfunc.para - Plot parametric distance functions

In tmcd82070/Rdistance: Density and Abundance from Distance-Sampling Surveys

plot.dfunc.para - Plot parametric distance functions

Description

Plot method for parametric line and point transect distance functions.

Usage

## S3 method for class 'dfunc.para'
plot(
  x,
  include.zero = FALSE,
  nbins = "Sturges",
  newdata = NULL,
  legend = TRUE,
  vertLines = TRUE,
  plotBars = TRUE,
  circles = FALSE,
  density = -1,
  angle = 45,
  xlab = NULL,
  ylab = NULL,
  border = TRUE,
  col = "grey85",
  col.dfunc = NULL,
  lty.dfunc = NULL,
  lwd.dfunc = NULL,
  ...
)

Arguments

x	An estimated detection function object, normally produced by calling dfuncEstim.
include.zero	Boolean value specifying whether to include 0 on the x-axis of the plot. A value of TRUE will include 0 on the left hand end of the x-axis regardless of the range of distances. A value of FALSE will plot only the observation strip (w.lo to w.hi).
nbins	Internally, this function uses hist to compute histogram bars for the plot. This argument is the breaks argument to hist. This can be either a vector giving the breakpoints between bars, the suggested number of bars (a single number), a string naming an algorithm to compute the number of bars, or a function to compute the number of bars. See hist for all options.
newdata	Data frame (similar to newdata parameter of lm) containing new values for covariates in the distance function. One distance function is computed and plotted for each row in the data frame. If newdata is NULL, a single distance function is plotted for mean values of all numeric covariates and mode values for all factor covariates.
legend	Logical scalar for whether to include a legend. If TRUE, a legend will be included on the plot detailing the covariate values used to generate the plot.
vertLines	Logical scalar specifying whether to plot vertical lines at w.lo and w.hi from 0 to the distance function.
plotBars	Logical scalar for whether to plot the histogram of distances behind the distance function. If FALSE, no histogram is plotted, only the distance function line(s).
circles	Logical scalar requesting the location of detection distances be plotted. If TRUE, open circles are plotted at predicted distance function heights associated with all detection distances. For computational simplicity, all distances are plotted for EVERY covariate class even though observed distances belong to only one covariate class. If FALSE, circles are not plotted.
density	If plotBars=TRUE, a vector giving the density of shading lines, in lines per inch, for the bars underneath the distance function, repeated as necessary to exceed the number of bars. Values of NULL or a number strictly less than 0 mean solid fill using colors from parameter col. If density = 0, bars are not filled and only the borders are rendered. If density > 0, bars are shaded with colors and angles from parameters col and angle.
angle	When density > 0, the slope of bar shading lines, given as an angle in degrees (counter-clockwise), repeated as necessary to exceed the number of bars.
xlab	Label for the x-axis
ylab	Label for the y-axis
border	The color of bar borders when bars are plotted, repeated as necessary to exceed the number of bars. A value of NA or FALSE means no borders. If bars are shaded with lines (i.e., density>0), border = TRUE uses the same color for the border as for the shading lines. Otherwise, fill color or shaded line color are specified in col while border color is specified in border.
col	A vector of bar fill colors or line colors when bars are drawn and density != 0, repeated as necessary to exceed the number of bars. Also used for the bar borders when border = TRUE.
col.dfunc	Color of the distance function(s). If only one distance function (one line) is being plotted, the default color is "red". If covariates or newdata are present, the default value uses graphics::rainbow(n), where n is the number of plotted distance functions. Otherwise, col.dfunc is replicated to the required length. Plot all distance functions in the same color by setting col.dfunc to a scalar. Plot blue-red pairs of distance functions by setting col.dfunc = c("blue", "red"). Etc.
lty.dfunc	Line type of the distance function(s). If covariates or newdata is present, the default uses line types to 1:n, where n is the number of plotted distance functions. Otherwise, lty.dfunc is replicated to the required length. Plot solid lines by specifying lty.dfunc = 1. Plot solid-dashed line pairs by specifying lty.dfunc = c(1,2). Etc.
lwd.dfunc	Line width of the distance function(s), replicated to the required length. Default is 2 for all lines.
...	When bars are plotted, this routine uses graphics::barplot to draw the plotting region and bars. When bars are not plotted, this routine sets up the plot with graphics::plot. ... can be any argument to barplot or plot EXCEPT width, ylim, xlim, density, angle, and space. For example, set the main title with main = "Main Title".

Value

The input distance function is returned, with two additional components than can be used to reconstruct the plotted bars. (To obtain values of the plotted distance functions, use predict with type = "distances".) The additional components are:

barHeights	A vector containing the scaled bar heights drawn on the plot.
barWidths	A vector or scalar of the bar widths drawn on the plot, with measurement units.

Re-plot the bars with barplot( return$barHeights, width = return$barWidths ).

See Also

plot.dfunc

Examples

# Example data
set.seed(87654)
x <- rnorm(1000, mean=0, sd=20)
x <- x[x >= 0]
x <- units::set_units(x, "ft")
Df <- data.frame(transectID = "A"
               , distance = x
                ) |> 
  dplyr::nest_by( transectID
               , .key = "detections") |> 
  dplyr::mutate(length = units::set_units(1,"mi"))
attr(Df, "detectionColumn") <- "detections"
attr(Df, "obsType") <- "single"
attr(Df, "transType") <- "line"
attr(Df, "effortColumn") <- "length"
is.RdistDf(Df) # TRUE

# Estimation
dfunc <- dfuncEstim(Df
                  , formula = distance~1
                  , likelihood="halfnorm")
plot(dfunc)
plot(dfunc, nbins=25)

tmcd82070/Rdistance documentation built on April 13, 2025, 1:38 p.m.