CODEWITHSUNDEEP
rggplot2
beginner_
beginner_

Reputation: 7622

R ggplot2: Draw diagonal lines on log-scale

I had a graph created with default R-plot functionality but now want to change to ggplot2 mainly because I want to use ggrepel to place labels correctly and non-overlapping.

My old plot contains diagonal lines which I need to keep. They are ploted like this:

for (i in -5:10) {
    abline(a= i, b= 1, lty = 5)
}

The issues I have now are:

  1. How do I do this for-loop with ggplot2 so I don't need to add all the lines expliclty?

  2. How do I actually created the lines correctly?

    geom_abline(slope=1, intercept=10)

Does not work as expected, probably due to log10 scale. So how can I draw diagonal lines on log10 scales correctly?

Upvotes: 1

Views: 1285

Answers (1)

beginner_
beginner_

Reputation: 7622

It actually works fine. This issue is directly related to my other issue about x and y axis limits. Per default the plot draws a bigger area than the x and y limits define (who thought this was a good idea???). And therefore the intercepts look wrong but the actually are ok.

If I set expand = c(0, 0) for both axis, then the intercept is also looks fine because that only draws to the limits.

The solution for multiple lines is a intercept list:

 geom_abline(slope=1, intercept=(-3):(5)

Upvotes: 1

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