Experiment
GeomBarbell <- ggproto("GeomBarbell", Geom,
required_aes = c("x", "y", "xend", "yend"),
default_aes = aes(
colour = "black",
linewidth = .5,
size = 2,
linetype = 1,
shape = 19,
fill = NA,
alpha = NA,
stroke = 1
),
draw_panel = function(data, panel_params, coord, ...) {
# Transformed data for the points
point1 <- transform(data)
point2 <- transform(data, x = xend, y = yend)
# Return all three components
grid::gList(
GeomSegment$draw_panel(data, panel_params, coord, ...),
GeomPoint$draw_panel(point1, panel_params, coord, ...),
GeomPoint$draw_panel(point2, panel_params, coord, ...)
)
}
)
ggplot(cars) +
aes(speed, dist, xend = speed + 2, yend = dist) +
stat_identity(geom = GeomBarbell)
combine_geoms <- function(geom1 = GeomPoint, geom2 = GeomText){
GeomCombo2 <- ggproto("GeomCombo2", Geom,
# required_aes = unique(c(geom1$required_aes, geom2$required_aes)),
default_aes = modifyList(geom1$default_aes, geom2$default_aes),
draw_panel = function(data, panel_params, coord, ...) {
# Return all three components
grid::gList(
geom1$draw_panel(data, panel_params, coord, ...),
geom2$draw_panel(data, panel_params, coord, ...)
)
}
)
GeomCombo2
}
library(ggplot2)
ggplot(cars) +
aes(speed, dist, label = speed) +
stat_identity(geom = combine_geoms(), alpha = .5)
library(ggplot2)
ggplot(cars) +
aes(speed, dist, label = speed) +
stat_identity(geom = combine_geoms(GeomPoint, GeomLabel),
alpha = .5,
hjust = 1)
ggplot(cars) +
aes(speed, dist, label = speed) +
stat_identity(geom = combine_geoms(GeomPoint, GeomTile),
alpha = .5,
hjust = 1)
## Warning in stat_identity(geom = combine_geoms(GeomPoint, GeomTile), alpha =
## 0.5, : Ignoring unknown parameters: `hjust`
## Error in `stat_identity()`:
## ! Problem while converting geom to grob.
## ℹ Error occurred in the 1st layer.
## Caused by error in `unit()`:
## ! 'x' and 'units' must have length > 0