说我有以下数据框:
# Set seed for RNG
set.seed(33550336)
# Create toy data frame
loc_x <- c(a = 1, b = 2, c = 3)
loc_y <- c(a = 3, b = 2, c = 1)
scaling <- c(temp = 100, sal = 10, chl = 1)
df <- expand.grid(loc_name = letters[1:3],
variables = c("temp", "sal", "chl"),
season = c("spring", "autumn")) %>%
mutate(loc_x = loc_x[loc_name],
loc_y = loc_y[loc_name],
value = runif(nrow(.)),
value = value * scaling[variables])
看起来像
# > head(df)
# loc_name variables season loc_x loc_y value
# 1 a temp spring 1 3 86.364697
# 2 b temp spring 2 2 35.222573
# 3 c temp spring 3 1 52.574082
# 4 a sal spring 1 3 0.667227
# 5 b sal spring 2 2 3.751383
# 6 c sal spring 3 1 9.197086
我想使用variables
和season
将这些数据绘制在构面网格中,以定义面板,如下所示:
g <- ggplot(df) + geom_point(aes(x = loc_name, y = value), size = 5)
g <- g + facet_grid(variables ~ season)
g
如您所见,不同的variables
具有不同的比例。因此,我使用scales = "free"
来解决这个问题。
g <- ggplot(df) + geom_point(aes(x = loc_name, y = value), size = 5)
g <- g + facet_grid(variables ~ season, scales = "free")
g
非常方便。现在,说我想这样做,但是用loc_x
和loc_y
绘制点,并用颜色而不是y位置表示value
:
g <- ggplot(df) + geom_point(aes(x = loc_x, y = loc_y, colour = value),
size = 5)
g <- g + facet_grid(variables ~ season, scales = "free")
g <- g + scale_colour_gradient2(low = "#3366CC",
mid = "white",
high = "#FF3300",
midpoint = 50)
g
请注意,颜色刻度不是免费的,并且像第一个数字一样,sal
和chl
的值不易读取。
我的问题:是否可以做scales = "free"
的等效项,但是要使用颜色,以便每一行(在这种情况下)都有单独的颜色条?或者,我是否必须绘制每个变量(即图中的行)并使用cowplot
之类的变量将它们修补在一起?
答案 0 :(得分:2)
使用dplyr
的开发版本:
library(dplyr)
library(purrr)
library(ggplot2)
library(cowplot)
df %>%
group_split(variables, season) %>%
map(
~ggplot(., aes(loc_x, loc_y, color = value)) +
geom_point(size = 5) +
scale_colour_gradient2(
low = "#3366CC",
mid = "white",
high = "#FF3300",
midpoint = median(.$value)
) +
facet_grid(~ variables + season, labeller = function(x) label_value(x, multi_line = FALSE))
) %>%
plot_grid(plotlist = ., align = 'hv', ncol = 2)