ggplot2 wrapper to to plot wind speed/direction frequencies and other statistics

Using summary_wind() to calculate und plot summary statisitics over wind direction and wind velocity bins. Primarily plots wind speed/direction frequencies. Each bin is colour-coded depending on the frequency of measurements. Bins can also be used to show the concentration of pollutants using a range of commonly used statistics.

Usage

ggpolarfreq(
  data,
  ws,
  wd,
  z = NULL,
  wd_binwidth = 45,
  ws_binwidth = 1,
  ws_max = NA,
  groupings = grp(),
  fun = "frequency",
  fun.args = list(),
  nmin = 1,
  fill_scale = scale_fill_viridis_c(labels = scales::percent),
  bg = NULL,
  calm = NA,
  calm.prefix = "Calm\n",
  calm.accuracy = 1,
  calm.color = "black",
  calm.size = 3.88,
  yexpand = 0.2,
  ...
)

Arguments

data

a data.frame or tibble containing the data (wide format)

ws

NULL or symbol giving the wind velocity parameter name (wind velocity preferably in m/s)

wd

symbol giving the wind direction parameter name

z

symbol giving the parameter name to be summarised

wd_binwidth

width of the wind direction bins in degrees wind direction (must fullfill binwidth %in% 360 / c(4, 8, 16, 32))

ws_binwidth

width of the wind speed bins

ws_max

if ws_max is specified, a bin with >ws_max will be included

groupings

additional groupings. Use helper grp() to create

fun

function or list of functions for summary.

fun.args

a list of extra arguments passed on to fun.

nmin

numeric, minimum number of values for fun, if n < nmin: NA is returned

fill_scale

ggplot2 discrete fill scale, e.g. ggplot2::scale_fill_gradientn()

bg

bg raster map, e.g. ggmap object as plot background

calm

if specified as numeric all windspeed below this value will be treated as calm and the proportion will be displayed as text in the center. The color, size of the text can be supplied with calm.size and calm.color. A prefix for the text can be defined with calm.prefix and the accuracy of the number with calm.accuracy

calm.prefix

prefix for the calm text as string. Supplied to scales::label_percent() as argument.

calm.accuracy

A number to round to. Use (e.g.) 0.01 to show 2 decimal places of precision. If NULL uses a heuristic that should ensure breaks have the minimum number of digits needed to show the difference between adjacent values.

calm.color

text color

calm.size

text size

yexpand

size of the empty calm circle in the center as percentage of the y scale

...

Other arguments passed on to ggplot2::geom_bar(). Used to set an aesthetic to a fixed value. Defaults are color = "white", width = 1, size = 0.25

Value

ggplot2::ggplot() object

Examples

library(ggplot2)

fn <- rOstluft.data::f("Zch_Schimmelstrasse_2010-2014.csv")

data <-
  rOstluft::read_airmo_csv(fn) %>%
  rOstluft::rolf_to_openair() %>%
  openair::cutData(type = "season")

# data with empty sectors
npoints <- 1000
data2 <- tibble::tibble(
  wd = runif(npoints, 90, 315),
  ws = runif(npoints, 0, 6)
)

# more bin, wider bars
ggpolarfreq(data2, ws, wd, wd_binwidth = 22.5, width = 1)


# squish wind speed
ggpolarfreq(data2, ws, wd, ws_max = 4)


# add a lower limit for wind speed (calm)
ggpolarfreq(data2, ws, wd, ws_max = 4, calm = 0.5)


# with real data
ggpolarfreq(data, ws, wd, ws_max = 2, ws_binwidth = 0.5)


# use grp for faceting
ggpolarfreq(data, ws, wd, ws_max = 2, ws_binwidth = 0.5, groupings = grp(season)) +
  facet_wrap(vars(season))


# show the frequency of a pollutant measurement
ggpolarfreq(
  data = data,
  ws = ws,
  wd = wd,
  z = "NOx",
  ws_max = 2,
  ws_binwidth = 0.5,
) + labs(title = "Frequency of NOx Measurements")


ggpolarfreq(
  data = data,
  ws = ws,
  wd = wd,
  z = "NOx",
  fun = "n",
  ws_max = 2,
  ws_binwidth = 0.5,
  fill_scale = scale_fill_viridis_c(limits=c(1, NA), na.value = "grey92")
) + labs(title = "Numbers of NOx Measurements")


# use z and provide a stat function, also provide fill_scale for
# correct formating
ggpolarfreq(
  data = data,
  ws = ws,
  wd = wd,
  z = "NOx",
  fun = "mean",
  fun.args = list(na.rm = TRUE),
  ws_max = 2,
  ws_binwidth = 0.5,
  fill_scale = scale_fill_viridis_c()
) + labs(title = "Mean value of NOx")


ggpolarfreq(
  data = data,
  ws = ws,
  wd = wd,
  z = "NOx",
  fun = ~quantile(., probs = 0.95),
  fun.args = list(na.rm = TRUE),
  ws_max = 2,
  ws_binwidth = 0.5,
  fill_scale = scale_fill_viridis_c()
) + labs(title = "95% Percentile of NOx")