CODEWITHSUNDEEP
rggplot2
Paul
Paul

Reputation: 105

Check if y-axis begins at zero

I want to determine if a plot generated by ggplot begins at zero.

I am generating a couple hundred reports that each have thirty or more charts in them. I am content with ggplot's defaults for when a plot starts at zero and when it doesn't, but I want to add a caption that draws the reader's attention to this fact.

Something like:

labs(caption = ifelse(XXXXX, "Note: y-axis does not begin at zero", ""))

But I have no clue what my test should be.

Upvotes: 6

Views: 46

Answers (1)

thc
thc

Reputation: 9705

Try this:

library(ggplot2)

g <- ggplot(data.frame(x=1:10, y=0:9), aes(x=x,y=y)) + geom_point()
yrange <- ggplot_build(g)$layout$panel_params[[1]]$y.range
if(yrange[1] <= 0) g <- g + labs(caption = "Note: y-axis does not begin at zero")
plot(g)

Upvotes: 4

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