Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
930 views
in Technique[技术] by (71.8m points)

r - ggplot kernal density plot lines overlapping improperly

The colors in my density plot are wrong! I can't figure out why.

Here is my data: https://pastebin.com/0jqHgvxx

data %>%
  ggplot(aes(x=amountremain, color=black)) +
  geom_density()  

enter image description here

When I check the raw data, I see that the red peak at x=0 is correct but the max x value corresponds to the a y-value for the red not blue line.

The max x value for black = TRUE is 162414.6, max x for black = FALSE is 253021.3 so the tail should be red not blue.

b <- unclass(density(data$amountremain[data$black==FALSE]))
max(b$y)
max(b$x)
[1] 0.0003079798
[1] 253021.3
a <- unclass(density(data$amountremain[data$black==TRUE]))
max(a$y)
max(a$x)
[1] 0.0002832889
[1] 162414.6

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

If you look at a different scale on the y-axis you can see that the last non-zero value of TRUE is just about 160000, while the last non-zero value of FALSE is about 250000 as it should be.

So the representation is correct but it is difficult to see the tails.

To see:

data %>% 
  ggplot(aes(x=amountremain, color=black)) +
  geom_density() + 
  ylim(0, 10^-5)

EDIT


@MrFlick explained why the line doesn't break. If your goal is to interrupt the distribution of TRUE on the last value, one possible solution is to create two distinct density dataframes:

to_dens <- function(df) {
  d <- density(df)
  df_d <- tibble(x = d$x, y = d$y)
  return(df_d)
}

df1 <- df %>% 
  filter(black == TRUE) %>% 
  summarise(to_dens(amountremain))

df2 <- df %>% 
  filter(black == FALSE) %>% 
  summarise(to_dens(amountremain))

ggplot() + 
  geom_line(data = df1, aes(x = x, y = y), col = "steelblue3") +
  geom_line(data = df2, aes(x = x, y = y), col = "firebrick2")

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...