I have got a plot with 3 lines as follows:
我有一个3行的情节如下：
a = data.frame(time = c(1:100), x = rnorm(100))
b = data.frame(time = c(1:100), y = rnorm(100))
c = data.frame(time = c(1:100), z = rnorm(100))
plot(a$time, a$x, type = 'l')
lines(b$time, b$y, type = 'l')
lines(c$time, c$z, type = 'l')
I need to fill the area between the lowest and maximum value of the lines so that I get a unique polygon of a given colour.
我需要在线的最低值和最大值之间填充区域，以便获得给定颜色的唯一多边形。
I know about the polygon function but I do not know how to use it in this case.
我知道多边形函数，但在这种情况下我不知道如何使用它。
Any suggestion? thanks
有什么建议吗？谢谢
1 个解决方案
#1
1
Here is an approach:
这是一种方法：
a = data.frame(time = c(1:100), x = rnorm(100))
b = data.frame(time = c(1:100), y = rnorm(100))
c = data.frame(time = c(1:100), z = rnorm(100))
calculate the pmin and pmax:
计算pmin和pmax：
min_a <- pmin(a, b, c)
max_a <- pmax(a, b, c)
construct the polygon as usual:
像往常一样构造多边形：
polygon(c(c$time, rev(c$time)), c(max_a$x ,rev(min_a$x)), col = rgb(1, 0, 0,0.5) )
or using ggplot:
或使用ggplot：
library(tidyverse)
data.frame(a, b, c) %>% #combine the three data frames
group_by(time) %>% # group by time for next step
mutate(max = max(x, y, z), # calculate max of x, y, z in each time
min = min(x, y, z)) %>% #same as above
select(-time.1, - time.2) %>% #discard redundant columns
gather(key, value, 2:4) %>% #convert to long format so you can color by key in the geom line call
ggplot()+
geom_ribbon(aes(x = time, ymin= min, ymax = max), fill= "red", alpha = 0.3)+
geom_line(aes(x = time, y = value, color = key))
#1
1
Here is an approach:
这是一种方法：
a = data.frame(time = c(1:100), x = rnorm(100))
b = data.frame(time = c(1:100), y = rnorm(100))
c = data.frame(time = c(1:100), z = rnorm(100))
calculate the pmin and pmax:
计算pmin和pmax：
min_a <- pmin(a, b, c)
max_a <- pmax(a, b, c)
construct the polygon as usual:
像往常一样构造多边形：
polygon(c(c$time, rev(c$time)), c(max_a$x ,rev(min_a$x)), col = rgb(1, 0, 0,0.5) )
or using ggplot:
或使用ggplot：
library(tidyverse)
data.frame(a, b, c) %>% #combine the three data frames
group_by(time) %>% # group by time for next step
mutate(max = max(x, y, z), # calculate max of x, y, z in each time
min = min(x, y, z)) %>% #same as above
select(-time.1, - time.2) %>% #discard redundant columns
gather(key, value, 2:4) %>% #convert to long format so you can color by key in the geom line call
ggplot()+
geom_ribbon(aes(x = time, ymin= min, ymax = max), fill= "red", alpha = 0.3)+
geom_line(aes(x = time, y = value, color = key))