从分箱数据生成直方图和密度 plot

Question

I've binned some data and currently have a dataframe that consists of two columns, one that specifies a bin range and another that specifies the frequency like this:-

> head(data)
      binRange Frequency
1    (0,0.025]        88
2 (0.025,0.05]        72
3 (0.05,0.075]        92
4  (0.075,0.1]        38
5  (0.1,0.125]        20
6 (0.125,0.15]        16

I want to plot a histogram and density plot using this but I can't seem to find a way of doing so without having to generate new bins etc. Using this solution here I tried to do the following:-

p <- ggplot(data, aes(x= binRange, y=Frequency)) + geom_histogram(stat="identity")

but it crashes. Anyone know of how to deal with this?

Thank you

Answer 1

the problem is that ggplot doesnt understand the data the way you input it, you need to reshape it like so (I am not a regex-master, so surely there are better ways to do is):

df <- read.table(header = TRUE, text = "
                 binRange Frequency
1    (0,0.025]        88
2 (0.025,0.05]        72
3 (0.05,0.075]        92
4  (0.075,0.1]        38
5  (0.1,0.125]        20
6 (0.125,0.15]        16")

library(stringr)
library(splitstackshape)
library(ggplot2)
# extract the numbers out,
df$binRange <- str_extract(df$binRange, "[0-9].*[0-9]+")

# split the data using the , into to columns:
# one for the start-point and one for the end-point
df <- cSplit(df, "binRange")

# plot it, you actually dont need the second column
ggplot(df, aes(x = binRange_1, y = Frequency, width = 0.025)) +
    geom_bar(stat = "identity", breaks=seq(0,0.125, by=0.025))

or if you don't want the data to be interpreted numerically, you can just simply do the following:

df <- read.table(header = TRUE, text = "
                 binRange Frequency
1    (0,0.025]        88
2 (0.025,0.05]        72
3 (0.05,0.075]        92
4  (0.075,0.1]        38
5  (0.1,0.125]        20
6 (0.125,0.15]        16")

library(ggplot2)
ggplot(df, aes(x = binRange, y = Frequency)) + geom_bar(stat = "identity")

you won't be able to plot a density-plot with your data, given its not continous but rather categorical, thats why I actually prefer the second way of showing it,

Answer 2

You can try

library(ggplot2)
ggplot(df, aes(x = binRange, y = Frequency)) + geom_col()