CODEWITHSUNDEEP
rggplot2facet
Faheem Mitha
Faheem Mitha

Reputation: 6326

Independent facet grids based on multiple data sets

If I have two datasets on the same plot, can I have two independent facets on that plot, each corresponding to a different data set?

For example, in a scatter plot, one can split one data in the x direction, one can split the other data set in the y direction.

Consider, for example, the following code, where I am trying to split d1 for values of the X axis less than 0.5 and bigger than 0.5, and similarly for d2 and the y axis. This runs, but I don't understand why I get the result i do.

It is possible that ggplot2 is simply not designed to do this. I don't have an application in mind, I'm just trying to understand the limits of faceting, and playing with examples is easier than trying to understand the code.

library("ggplot2")

splitvec <- function(v)
{
  if(v<0.5)
    return("L")
  else if(v>=0.5)
    return("R")
}

set.seed(1)
x1 <-  runif(5, 0, 1)
y1 <-  runif(5, 0, 1)
xsplit <- sapply(x1, splitvec)
d1 = data.frame(x=x1, y=y1, X=xsplit)
x2 <-  runif(5, 0, 1)
y2 <-  runif(5, 0, 1)
ysplit <- sapply(y2, splitvec)
d2 = data.frame(x=x2, y=y2, Y=ysplit)

r = ggplot() +
    geom_point(data=d1, aes(x=x, y=y)) + facet_grid( ~ X) +
    geom_point(data=d2, aes(x=x, y=y)) + facet_grid(Y ~ .)

Upvotes: 3

Views: 3585

Answers (1)

agstudy
agstudy

Reputation: 121568

In this case you can do something like : 

       facet_grid(Y~X)

Since that grid faceting is applied sequentially. Note that you can't use facet_wrap in this case. Here I am rewriting your code to use different factors for each split variable (X,Y). 

d1$X <- ifelse(d1$x<0.5,'d1.L','d1.R') 
d2$Y <- ifelse(d2$x<0.5,'d2.L','d2.R')

It is better to use different colors for each data to understand what happens to your data.

r = ggplot() +
  geom_point(data=d1, aes(x=x, y=y),col='blue',size=10) +
  geom_point(data=d2, aes(x=x, y=y))+
  facet_grid(Y~X,scales="free")+
  theme(strip.text = element_text(size=20))

enter image description here

Upvotes: 4

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