CODEWITHSUNDEEP
rggplot2
adam.888
adam.888

Reputation: 7846

R saving contour lines into a dataframe

ggplot allows me to plot contour lines for a data series x and y:

library(ggplot2)
df <- data.frame(x=c(1:100),y=rnorm(100))
ggplot(df,aes(x=x,y=y))+geom_density2d()

I would like to be able to save the data output of the main four contour lines (95,75,50,25)max and (95,75,50,25)min in a dataframe. I would be grateful for your help. Perhaps there is a way of doing this directly, without using ggplot.

Upvotes: 2

Views: 541

Answers (1)

Didzis Elferts
Didzis Elferts

Reputation: 98509

Using function ggplot_build() around ggplot() object you can access all data used for the plotting. Data are stored in list element data.

p<-ggplot_build(ggplot(df,aes(x=x,y=y))+geom_density2d())

str(p$data)
List of 1
 $ :'data.frame':   1895 obs. of  6 variables:
  ..$ level: num [1:1895] 5e-04 5e-04 5e-04 5e-04 5e-04 5e-04 5e-04 5e-04 5e-04 5e-04 ...
  ..$ x    : num [1:1895] 1 2 3 4 5 ...
  ..$ y    : num [1:1895] 1.42 1.44 1.45 1.45 1.46 ...
  ..$ piece: int [1:1895] 1 1 1 1 1 1 1 1 1 1 ...
  ..$ group: Factor w/ 13 levels "1-001","1-002",..: 1 1 1 1 1 1 1 1 1 1 ...
  ..$ PANEL: int [1:1895] 1 1 1 1 1 1 1 1 1 1 ...

You can store those data as separate data frame.

gg<-p$data[[1]]
head(gg)
  level        x        y piece group PANEL
1 5e-04 1.000000 1.423926     1 1-001     1
2 5e-04 2.000000 1.435286     1 1-001     1
3 5e-04 3.000000 1.445293     1 1-001     1
4 5e-04 4.000000 1.454166     1 1-001     1
5 5e-04 5.000000 1.462106     1 1-001     1
6 5e-04 5.255343 1.463967     1 1-001     1

group and piece variables shows for which line each value belong (1 - outer lines, 13 - inner lines in this case).

Upvotes: 5

Related Questions