Modify a ggmatrix object by adding an ggplot2 object to all plots

Source: R/ggpairs_add.R

This operator allows you to add ggplot2 objects to a ggmatrix object.

add_to_ggmatrix(e1, e2, location = NULL, rows = NULL, cols = NULL)

Arguments

e1

An object of class ggnostic or ggplot

e2

A component to add to e1

location
"all", TRUE

All row and col combinations

"none"

No row and column combinations

"upper"

Locations where the column value is higher than the row value

"lower"

Locations where the row value is higher than the column value

"diag"

Locations where the column value is equal to the row value

matrix or data.frame

matrix values will be converted into data.frames.

  • A data.frame with the exact column names c("row", "col")

  • A data.frame with the number of rows and columns matching the plot matrix object provided. Each cell will be tested for a "truthy" value to determine if the location should be kept.

rows

numeric vector of the rows to be used. Will be used with cols if location is NULL

cols

numeric vector of the cols to be used. Will be used with rows if location is NULL

Details

If the first object is an object of class ggmatrix, you can add the following types of objects, and it will return a modified ggplot2 object.

  • theme: update plot theme

  • scale: replace current scale

  • coord: override current coordinate system

The + operator completely replaces elements with elements from e2.

add_to_ggmatrix gives you more control to modify only some subplots. This function may be replaced and/or removed in the future. [Experimental]

Examples

# small function to display plots only if it's interactive
p_ <- GGally::print_if_interactive
data(tips)

pm <- ggpairs(tips[, 2:4], ggplot2::aes(color = sex))
## change to black and white theme
pm + ggplot2::theme_bw()
#> `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.
#> `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

## change to linedraw theme
p_(pm + ggplot2::theme_linedraw())
## change to custom theme
p_(pm + ggplot2::theme(panel.background = ggplot2::element_rect(fill = "lightblue")))
## add a list of information
extra <- list(ggplot2::theme_bw(), ggplot2::labs(caption = "My caption!"))
p_(pm + extra)

## modify scale
p_(pm + scale_fill_brewer(type = "qual"))
## only first row
p_(add_to_ggmatrix(pm, scale_fill_brewer(type = "qual"), rows = 1:2))
## only second col
p_(add_to_ggmatrix(pm, scale_fill_brewer(type = "qual"), cols = 2:3))
## only to upper triangle of plot matrix
p_(add_to_ggmatrix(
  pm,
  scale_fill_brewer(type = "qual"),
  location = "upper"
))