Forcing a label with a 0 count in a barplot

0
votes

I am plotting a barplot for a summary data.frame consisting of ten records. Each record lists a size and a frequency for that size. One size class has a zero frequency.

However, when run, the zero-count class vanishes and instead of the full ten classes, only nine appear in the plot.

I've tried an as.numeric, but that renders as a decimal and doesn't reflect the factor value.

The ggpot2 code I am using is:

plt1 <- ggplot(szt, aes(x = as.factor(size, Freq))) + 
     geom_bar(stat = "identity") 

plt1 + xlab("Debitage Size, 5 mm class") + ylab("Frequency") + 
      ggtitle("Debitage Size Distribution by 5 mm class")

The data is:

   size Freq
1     1  196
2     2  261
3     3   77
4     4   26
5     5   14
6     6    9
7     7    4
8     8    0
9     9    1
10   10    2

> str(szt)
'data.frame':   10 obs. of  2 variables:
 $ size: Factor w/ 10 levels "1","2","3","4",..: 1 2 3 4 5 6 7 10 8 9
 $ Freq: num  196 261 77 26 14 9 4 0 1 2

As noted above, I wish to see all ten factors along the X-axis. However ggplot drops the zero-count element.

1
rggplot2

1 Answers

0
votes

@john welcome to SO. Please see here on how to create a minimum reproducible example. Try the following,

library(ggplot2)
df2<- data.frame(size = as.factor( c(1:10)), 
                     freq=c(196,200,77,26,14,9,4,0,1,2)
                 )
df2

R> df2
   size freq
1     1  196
2     2  200
3     3   77
4     4   26
5     5   14
6     6    9
7     7    4
8     8    0
9     9    1
10   10    2

ggplot(df2, aes(x = size, y=freq)) + 
  geom_bar(stat = "identity")

plot1