Customized coord_polar

The differences between ggplot2::coord_polar() and coord_polar2() are:

• Add a raster (image) as background. As example a map created with get_stadia_map()

• ggplot2::coord_polar() always adds an outer circle with r = 0.45 to the plot. This circle is removed.

Usage

coord_polar2(theta = "x", start = 0, direction = 1, clip = "on", bg = NULL)

Arguments

theta

variable to map angle to (x or y)

start

Offset of starting point from 12 o'clock in radians. Offset is applied clockwise or anticlockwise depending on value of direction.

direction

1, clockwise; -1, anticlockwise

clip

Should drawing be clipped to the extent of the plot panel? A setting of "on" (the default) means yes, and a setting of "off" means no. For details, please see coord_cartesian().

bg

raster for background image

Value

ggplot2 coord system

See also

ggplot2::coord_polar()

Examples

library(ggplot2)

fn <- rOstluft.data::f("Zch_Stampfenbachstrasse_2010-2014.csv")
data <- rOstluft::read_airmo_csv(fn) %>%
  rOstluft::rolf_to_openair()

data_summarized <- summary_wind(data, ws, wd, ws,
  ws_cutfun = cut_ws.fun(ws_max = 4, reverse = TRUE)
)

wind_rose <- ggplot(data_summarized, aes(x = wd, y = freq, fill = ws)) +
  geom_bar(stat = "identity", alpha = 0.8) +
  scale_y_continuous(
    limits = c(0, NA),
    expand = c(0,0, 0, 0),
    labels = scales::percent
  ) +
  scale_fill_viridis_d()

# background map
bbox <- bbox_lv95(2683141, 1249040, 500)
bg <- get_stadia_map(bbox)
#> ℹ © Stadia Maps © Stamen Design © OpenMapTiles © OpenStreetMap contributors.

wind_rose + coord_polar2(start = - 45 * pi / 360, bg = bg)


# removed outer circle
df <- tibble::tibble(x = factor(1:10), y = runif(10, 0, 100))

p <- ggplot(df, aes(x = x, y = y)) +
  geom_bar( stat = "identity") +
  scale_x_discrete() +
  theme(
    axis.line.x = element_line(colour = "red"),
    axis.line.y = element_line(colour = "orange"),
    panel.grid.major.x = element_line(colour = "blue"),
    panel.grid.major.y = element_line(colour = "darkgreen"),
    panel.grid.minor.y = element_line(colour = "darkolivegreen2")
  )

# default behaviour with no breaks
p + coord_polar() + scale_y_continuous()


p + coord_polar2() + scale_y_continuous()


# behavoiur with manuel breaks and limit
p + coord_polar() + scale_y_continuous(breaks = seq(0, 100, 20), limits = c(0, 200))


p + coord_polar2() + scale_y_continuous(breaks = seq(0, 100, 20), limits = c(0, 200))