How to show null data in barplot R

问题

I want to draw a barplot with in axis x the number of months and in axis y the value of a variable. The variable can be null for some months. How can I coerce the axis x to always show the 12 months?

With V a data frame like:

    month variable
    1  125
    2  45 
    3  158
    4  15
    5  58
    6  78
    7  89
    9  15
    10 85
    11 799
    12 55

Here in August (month 8) the variable is 0.

bp <- barplot(V[,2],  axes = FALSE)
axis(1, at = bp, labels=c("jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"))

Thanks

回答1:

You need to pad an NA at August (month 8). Simply use

bp <- barplot(append(V[,2], NA, 7),  axes = FALSE)
axis(1, at = bp, labels=c("jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"))

More generally I would do this:

x <- rep(NA, 12)
x[V$month] <- V$variable
bp <- barplot(x, axes = FALSE)
axis(1, at = bp, labels=c("jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"))

来源：https://stackoverflow.com/questions/38719788/how-to-show-null-data-in-barplot-r