Scatter plot of two variables — plot

This is a convenient quick scatter plot function for plotting any two variables x and y in a coin against each other. At a minimum, you must specify the data set and iCode of both x and y using the dsets and iCodes arguments.

Usage

plot_scatter(
  coin,
  dsets,
  iCodes,
  ...,
  by_group = NULL,
  alpha = 0.5,
  axes_label = "iCode",
  dset_label = TRUE,
  point_label = NULL,
  check_overlap = TRUE,
  nudge_y = 5,
  log_scale = c(FALSE, FALSE)
)

Arguments

coin: A coin object
dsets: A 2-length character vector specifying the data sets to extract v1 and v2 from, respectively (passed as dset argument to get_data(). Alternatively specify as a single string which will be used for both x and y.
iCodes: A 2-length character vector specifying the iCodes to use as v1 and v2, respectively (passed as iCodes argument to get_data(). Alternatively specify as a single string which will be used for both x and y.
...: Optional further arguments to be passed to get_data(), e.g. to specify which uCodes to plot.
by_group: A string specifying an optional group variable. If specified, the plot will be coloured by this grouping variable.
alpha: Transparency value for points between 0 and 1, passed to ggplot2.
axes_label: A string specifying how to label axes and legend. Either "iCode" to use the respective codes of each variable, or else "iName" to use the names (as specified in iMeta).
dset_label: Logical: if TRUE (default), also adds to the axis labels which data set each variable is from.
point_label: Specifies whether and how to label points. If "uCode", points are labelled with their unit codes, else if "uName", points are labelled with their unit names. Set NULL to remove labels (default).
check_overlap: Logical: if TRUE (default), point labels that overlap are removed - this results in a legible plot but some labels may be missing. Else if FALSE, all labels are plotted.
nudge_y: Parameter passed to ggplot which controls the vertical adjustment of the text labels if present.
log_scale: A 2-length logical vector specifying whether to use log axes for x and y respectively: if TRUE, a log axis will be used. Defaults to not-log.

Value

A ggplot2 object.

Details

Optionally, the scatter plot can be coloured by grouping variables specified in the coin (see by_group). Points and axes can be labelled using other arguments.

This function is powered by ggplot2 and outputs a ggplot2 object. To further customise the plot, assign the output of this function to a variable and use ggplot2 commands to further edit. See vignette("visualisation) for more details on plotting.

Examples

# build example coin
coin <- build_example_coin(up_to = "new_coin")
#> iData checked and OK.
#> iMeta checked and OK.
#> Written data set to .$Data$Raw

# scatter plot of Flights against Population
# coloured by GDP per capita
# log scale applied to population
plot_scatter(coin, dsets = c("uMeta", "Raw"),
             iCodes = c("Population", "Flights"),
             by_group = "GDPpc_group", log_scale = c(TRUE, FALSE))