stat_debug_group: Print to console data received by statistics as input

Description

stat_debug_group and stat_debug_panel apply a function to data and, most importantly, echo to the R console their data input or a summary of it.

Usage

stat_debug_group(
  mapping = NULL,
  data = NULL,
  geom = "null",
  fun.data = "I",
  fun.data.args = list(),
  dbgfun.data = "head",
  dbgfun.data.args = list(),
  geom.dbgfun.data = "head",
  geom.dbgfun.data.args = list(),
  geom.dbgfun.params = NULL,
  geom.dbgfun.params.args = list(),
  dbgfun.print = "print",
  dbgfun.print.args = list(),
  position = "identity",
  na.rm = FALSE,
  show.legend = FALSE,
  inherit.aes = TRUE,
  ...
)
stat_debug_panel(
  mapping = NULL,
  data = NULL,
  geom = "null",
  fun.data = "I",
  fun.data.args = list(),
  dbgfun.data = "head",
  dbgfun.data.args = list(),
  geom.dbgfun.data = "head",
  geom.dbgfun.data.args = list(),
  geom.dbgfun.params = NULL,
  geom.dbgfun.params.args = list(),
  dbgfun.print = "print",
  dbgfun.print.args = list(),
  position = "identity",
  na.rm = FALSE,
  show.legend = FALSE,
  inherit.aes = TRUE,
  ...
)

Value

A copy of its data input, which is an object of class

"data.frame" or inheriting from "data.frame".

Arguments

mapping: The aesthetic mapping, usually constructed with aes or aes_. Only needs to be set at the layer level if you are overriding the plot defaults.
data: A layer specific dataset - only needed if you want to override the plot defaults.
geom: The geometric object to use display the data
fun.data: A function taking a data frame as its first argument and returning a data frame. This function does the computations generating the value passed from the statistic to the downstream geometry.
fun.data.args: A named list of additional arguments to be passed to fun.data.
dbgfun.data, geom.dbgfun.data, geom.dbgfun.params: A functions used to summarise the data and parameters objects received as input by the statistic and geometry.
dbgfun.data.args, geom.dbgfun.data.args, geom.dbgfun.params.args: A named list of arguments.
dbgfun.print: A function used to print the summary of the data object received as input by the statistic, also visible to the geometry, and used by geom_debug().
dbgfun.print.args: A named list. Currently ignored!
position: The position adjustment to use for overlapping points on this layer
na.rm: a logical value indicating whether NA values should be stripped before the computation proceeds.
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.
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.
...: other arguments passed on to layer. This can include aesthetics whose values you want to set, not map. See layer for more details.

Computed variables

x: x at centre of range
y: y at centre of range
nrow: nrow() of data object
ncol: ncol() of data object
colnames: colnames() of data object
colclasses: class() of x and y columns in data object
group: all distinct values in group as passed in data object
PANEL: all distinct values in PANEL as passed in data object

Details

These stats are meant to be used for the side-effect of printing to the console the data object received as input by the compute_group() or compute_panel() function, or a summary of it. These data objects are the same as those received as input by any other statistics passed the same arguments. By default, the applied function is I(), the identity function.

In principle any geom can be passed as argument to override geom = "null". However, geom = "debug_panel" and geom = "debug_group" are treated as special cases and functions geom.dbgfun.data and geom.dbgfun.params, and lists geom.dbgfun.data.args and geom.dbgfun.params.args renamed and passed to the geometry. Arguments passed to these four formal parameters are not passed to other geometries.

Keep in mind that this stat sets default mappings only for the x and/or y aesthetics, additional mappings can be set using aes(), possibly together with after_stat().

Examples

Run this code

my.df <- data.frame(x = rep(1:10, 2),
                    y = rep(c(1,2), c(10,10)) + rnorm(20),
                    group = rep(c("A","B"), c(10,10)))

# by default head() is used to show the top rows of the data object
# and geom_null() to silence the data returned by the stat
ggplot(my.df, aes(x,y)) +
  geom_point() +
  stat_debug_group()

# geom_debug prints the data returned by the stat
ggplot(my.df, aes(x,y)) +
  geom_point() +
  stat_debug_group(geom = "debug_panel")

# geom_debug prints the data returned by the stat
ggplot(my.df, aes(x,y)) +
  geom_point() +
  stat_debug_group(geom = "debug_panel",
                   geom.dbgfun.params = "summary")

# to print only the the data returned by the stat
# we pass as summary function a function that always returns NULL
ggplot(my.df, aes(x,y)) +
  geom_point() +
  stat_debug_group(geom = "debug_panel",
                   dbgfun.data = function(x) {NULL})

ggplot(my.df, aes(x,y)) +
  geom_point() +
  stat_debug_group(aes(label = paste("group:", group)),
                   geom = "text")

# here we show all the data object
ggplot(my.df, aes(x,y)) +
  geom_point() +
  stat_debug_group(dbgfun.data = "I")

# with grouping
ggplot(my.df, aes(x,y, colour = group)) +
  geom_point() +
  stat_debug_group()

ggplot(my.df, aes(x,y, colour = group)) +
  geom_point() +
  stat_debug_panel()

ggplot(my.df, aes(x, y, colour = group)) +
  geom_point() +
  stat_debug_group(dbgfun.data = "nrow")

ggplot(my.df, aes(x, y)) +
  geom_point() +
  facet_wrap(~group) +
  stat_debug_group()

# by default head() is used to show the top rows of data object
ggplot(my.df, aes(group,y)) +
  geom_point() +
  stat_debug_group()

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