geom_contour2: 2d contours of a 3d surface
In eliocamp/meteoR: Tools for Easier Analysis of Meteorological Fields

geom_contour2

R Documentation

2d contours of a 3d surface

Description

Similar to ggplot2::geom_contour but it can label contour lines, accepts accepts a function as the breaks argument and and computes breaks globally instead of per panel.

Usage

geom_contour2(
  mapping = NULL,
  data = NULL,
  stat = "contour2",
  position = "identity",
  ...,
  lineend = "butt",
  linejoin = "round",
  linemitre = 1,
  breaks = MakeBreaks(),
  bins = NULL,
  binwidth = NULL,
  global.breaks = TRUE,
  na.rm = FALSE,
  na.fill = FALSE,
  skip = 1,
  margin = grid::unit(c(1, 1, 1, 1), "pt"),
  label.placer = label_placer_flattest(),
  show.legend = NA,
  inherit.aes = TRUE
)

stat_contour2(
  mapping = NULL,
  data = NULL,
  geom = "contour2",
  position = "identity",
  ...,
  breaks = MakeBreaks(),
  bins = NULL,
  binwidth = NULL,
  proj = NULL,
  clip = NULL,
  kriging = FALSE,
  global.breaks = TRUE,
  na.rm = FALSE,
  na.fill = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

Arguments

`mapping`	Set of aesthetic mappings created by `aes()`. If specified and `inherit.aes = TRUE` (the default), it is combined with the default mapping at the top level of the plot. You must supply `mapping` if there is no plot mapping.
`data`	The data to be displayed in this layer. There are three options: If `NULL`, the default, the data is inherited from the plot data as specified in the call to `ggplot()`. A `data.frame`, or other object, will override the plot data. All objects will be fortified to produce a data frame. See `fortify()` for which variables will be created. A `function` will be called with a single argument, the plot data. The return value must be a `data.frame`, and will be used as the layer data. A `function` can be created from a `formula` (e.g. `~ head(.x, 10)`).
`stat`	The statistical transformation to use on the data for this layer, either as a `ggproto` `Geom` subclass or as a string naming the stat stripped of the `stat_` prefix (e.g. `"count"` rather than `"stat_count"`)
`position`	Position adjustment, either as a string naming the adjustment (e.g. `"jitter"` to use `position_jitter`), or the result of a call to a position adjustment function. Use the latter if you need to change the settings of the adjustment.
`...`	Other arguments passed on to `layer()`. These are often aesthetics, used to set an aesthetic to a fixed value, like `colour = "red"` or `size = 3`. They may also be parameters to the paired geom/stat.
`lineend`	Line end style (round, butt, square).
`linejoin`	Line join style (round, mitre, bevel).
`linemitre`	Line mitre limit (number greater than 1).
`breaks`	One of: A numeric vector of breaks A function that takes the range of the data and binwidth as input and returns breaks as output
`bins`	Number of evenly spaced breaks.
`binwidth`	Distance between breaks.
`global.breaks`	Logical indicating whether `breaks` should be computed for the whole data or for each grouping.
`na.rm`	If `FALSE`, the default, missing values are removed with a warning. If `TRUE`, missing values are silently removed.
`na.fill`	How to fill missing values. `FALSE` for letting the computation fail with no interpolation `TRUE` for imputing missing values with Impute2D A numeric value for constant imputation A function that takes a vector and returns a numeric (e.g. `mean`)
`skip`	number of contours to skip for labelling (e.g. `skip = 1` will skip 1 contour line between labels).
`margin`	the margin around labels around which contour lines are clipped to avoid overlapping.
`label.placer`	a label placer function. See `label_placer_flattest()`.
`show.legend`	logical. Should this layer be included in the legends? `NA`, the default, includes if any aesthetics are mapped. `FALSE` never includes, and `TRUE` always includes. It can also be a named logical vector to finely select the aesthetics to display.
`inherit.aes`	If `FALSE`, overrides the default aesthetics, rather than combining with them. This is most useful for helper functions that define both data and aesthetics and shouldn't inherit behaviour from the default plot specification, e.g. `borders()`.
`geom`	The geometric object to use to display the data, either as a `ggproto` `Geom` subclass or as a string naming the geom stripped of the `geom_` prefix (e.g. `"point"` rather than `"geom_point"`)
`proj`	The projection to which to project the contours to. It can be either a projection string or a function to apply to the whole contour dataset.
`clip`	A simple features object to be used as a clip. Contours are only drawn in the interior of this polygon.
`kriging`	Whether to perform ordinary kriging before contouring. Use this if you want to use contours with irregularly spaced data. If `FALSE`, no kriging is performed. If `TRUE`, kriging will be performed with 40 points. If a numeric, kriging will be performed with `kriging` points.

Aesthetics

geom_contour2 understands the following aesthetics (required aesthetics are in bold):

Aesthetics related to contour lines:

x
y
z
alpha
colour
group
linetype
size
weight

Aesthetics related to labels:

label
label_colour
label_alpha
label_size
family
fontface

Computed variables

level: height of contour

Examples



library(ggplot2)

# Breaks can be a function.
ggplot(reshape2::melt(volcano), aes(Var1, Var2)) +
    geom_contour2(aes(z = value, color = after_stat(level)),
                  breaks = AnchorBreaks(130, binwidth = 10))

# Add labels by supplying the label aes.
ggplot(reshape2::melt(volcano), aes(Var1, Var2)) +
    geom_contour2(aes(z = value, label = after_stat(level)))

ggplot(reshape2::melt(volcano), aes(Var1, Var2)) +
    geom_contour2(aes(z = value, label = after_stat(level)),
                  skip = 0)

# Use label.placer to control where contours are labelled.
ggplot(reshape2::melt(volcano), aes(Var1, Var2)) +
    geom_contour2(aes(z = value, label = after_stat(level)),
                      label.placer = label_placer_n(n = 2))

# Use the rot_adjuster argument of the placer function to
# control the angle. For example, to fix it to some angle:
ggplot(reshape2::melt(volcano), aes(Var1, Var2)) +
    geom_contour2(aes(z = value, label = after_stat(level)),
                  skip = 0,
                  label.placer = label_placer_flattest(rot_adjuster = 0))

eliocamp/meteoR documentation built on Feb. 19, 2024, 1:11 p.m.