如何在R图例中显示数据值的计算

Question

Here's a fiddle for a simplified version of a plot I am trying to generate.

On line 44 the plot points are sized according to 1/Error:

main_aes = aes(x = Date, y = Popular_Support, size=1/Error)

But instead of displaying 1/Error values in the legend, I want it to display Sample Size which is 1/Error^2 , which the legend title being Sample Size .

I only want this displayed in the legend, but I still want the original values to weight the point sizes.

How can I do this? How can I perform a calculation on the legend text that is displayed and change the legend title?

Answer 1

You can do this as follows:

plot + scale_size_continuous(breaks=seq(40,70,10), labels=seq(40,70,10)^2,
                             name="Sample Size")

Also, plot is an R function, so it's probably better to use a different name for your plot objects.