Intro Thoughts
Status Quo
library(tidyverse)
ggplot(cars) +
aes(speed, dist) +
geom_point(size = .15) ->
base; base
compute_mean <- function(data, scales){
data %>%
summarise(x = mean(x),
y = mean(y))
}
######## groupwise computation via compute group ####
StatMeangroup <- ggproto(`_class` = "StatMeangroup",
`_inherit` = Stat,
compute_group = compute_mean)
base +
layer(geom = "point",
stat = StatMeangroup,
position = "identity") +
aes(color = speed > 15)
######## panel-wise computation by defining compute panel #####
StatMeanpanel <- ggproto(`_class` = "StatMeanpanel",
`_inherit` = Stat,
compute_panel = compute_mean)
base +
layer(geom = "point",
stat = StatMeanpanel,
position = "identity") +
aes(color = speed > 15)
last_plot() +
facet_wrap(facets = vars(speed > 15))
######## layer wise computation via compute_layer??? ####
StatMeanlayer <- ggproto(`_class` = "StatMeanlayer",
`_inherit` = Stat,
compute_layer = compute_mean)
# expect a point in each facet that computes the mean for the entire layer.
base +
layer(geom = "point",
stat = StatMeanlayer,
position = "identity") +
aes(color = speed > 15) +
facet_wrap(facets = vars(speed > 15))
## Error:
## ! Problem while computing stat.
## ℹ Error occurred in the 2nd layer.
## Caused by error in `compute_layer()`:
## ! unused argument (<environment>)
Experiment
library(tidyverse)
compute_mean <- function(data, ...){
data %>%
distinct(PANEL) ->
panel_df
data %>%
summarise(x = mean(x),
y = mean(y)) %>%
crossing(panel_df)
}
######## groupwise computation via compute group ####
StatMeanlayer <- ggproto(`_class` = "StatMeanlayer",
`_inherit` = Stat,
compute_layer = compute_mean)
ggplot(cars) +
aes(speed, dist) +
geom_point(size = .15) +
layer(geom = "point",
stat = StatMeanlayer,
position = "identity")
last_plot() +
facet_wrap(facets = vars(speed > 10))
layer_data(i = 2)
## # A tibble: 2 × 9
## x y PANEL shape colour size fill alpha stroke
## <dbl> <dbl> <fct> <dbl> <chr> <dbl> <lgl> <lgl> <dbl>
## 1 15.4 43.0 1 19 black 1.5 NA NA 0.5
## 2 15.4 43.0 2 19 black 1.5 NA NA 0.5
last_plot() +
aes(color = dist > 30)
