R : pass Graph as parameter to a function

Question

I have a decent looking graph ,which I plotted using

r <- ggplot(data=data2.Gurgaon,aes(x=createdDate,y=count))+geom_point()

Now i want to h

Answer 1

You cannot select a subset of the data within the aesthetics part of a ggplot function, as you are trying to do. However you can achieve this by extracting the original data from the ggplot object, subsetting it and using the subset in the rest of the function.

r <- ggplot(data=mtcars,aes(x=cyl,y=drat))+geom_point()

 graphPoint <- function(graph,point) {
  g <- graph
  data_subset <- g$data[point, ]
  g <- g+geom_point(data = data_subset, 
                    aes(x=cyl,y=drat),pch=1,size=8,col='black')
  g <- g+ geom_point(data = data_subset,
                     aes(x=cyl,y=drat),pch=16,size=5,col='red')
  g
 }

 graphPoint(r, point = 2)

PS for upcoming posts I would advise you to make a reproducible example by using data that is generally accessible, like the mtcars data. This would make it easier to help you out.