Calculate psychrometric properties of moist air

stat_relhum(
  mapping = NULL,
  data = NULL,
  geom = "point",
  position = "identity",
  ...,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

stat_wetbulb(
  mapping = NULL,
  data = NULL,
  geom = "point",
  position = "identity",
  ...,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

stat_vappres(
  mapping = NULL,
  data = NULL,
  geom = "point",
  position = "identity",
  ...,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

stat_specvol(
  mapping = NULL,
  data = NULL,
  geom = "point",
  position = "identity",
  ...,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

stat_enthalpy(
  mapping = NULL,
  data = NULL,
  geom = "point",
  position = "identity",
  ...,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

Arguments

mapping	Set of aesthetic mappings created by `aes()` or `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)`).
geom	The geometric object to use display the data
position	Position adjustment, either as a string, or the result of a call to a position adjustment function.
...	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.
na.rm	If `FALSE`, the default, missing values are removed with a warning. If `TRUE`, missing values are silently removed.
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()`.

Details

stat_relhum requires an extra relhum aesthetics for relative humidity in range [0, 100] in %
stat_wetbulb requires an extra wetbulb aesthetics for wet-bulb temperature in degree_F [IP] or degree_C [SI]
stat_vappres requires an extra vappres aesthetics for partial pressure of water vapor in moist air in Psi [IP] or Pa [SI]
stat_specvol requires an extra specvol aesthetics for specific volume of moist air in ft3 lb-1 of dry air [IP] or in m3 kg-1 of dry air [SI]
stat_enthalpy requires an extra enthalpy aesthetics for moist air enthalpy in Btu lb-1 [IP] or J kg-1

What these ggplot2::ggproto() objects do are to take input values, calculate the corresponding humidity ratio and replace the y aesthetic values in each group.

All of stats above requires two additional aesthetics:

units: A single string indicating the units sytem to use. Should be either "SI" or "IP" or waiver()which uses the value from the parent plot. Default:waiver()`
pres: A single number indicating the atmosphere pressure in Pa [SI] or Psi [IP]. If waiver(), the pressure calculated from the parent plot's altitude value will be used. Default: waiver()

However, when these stats are used inside a ggplot geom_* as the stat argument, both units and pres have to be specified.

Examples

p <- ggpsychro() + geom_grid_relhum() # add relative humidity grid lines

# draw a point with dry-bulb at 30C and relative humidity at 60%
p + geom_point(aes(x = 30, relhum = 0.6), stat = "relhum", size = 5)

# draw a constant relative humidity line of 60% with dry-bulb from 20C to 30C
## use stat_* directly
p + stat_relhum(geom = "line", aes(x = 20:30, relhum = 0.6), size = 2)
## OR
## use as thet `stat` argument inside an ggplot `geom_*` function
p + geom_line(aes(x = 20:30, relhum = 0.6), stat = "relhum")