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rggplot2pca

PCA plot and Proportion of Variance table in one ggplot2 plot - R

I have a PCA plot and the Proportion of Variance table. When I plot the mentioned table (using tableGrob) above the plot there is a lot of space between them. How can I attached them "closer" and align the table to the upper right side of the PCA plot?

library(data.table)
library(MASS)
library(ggplot2)
library(reshape2)
library(grid)
library(gridExtra) 
   
#PCA  
iris.pca <- prcomp(iris[,1:4], scale. = TRUE)
dataIris.pca  <- data.frame(summary(iris.pca)$importance) 
dat <- data.table(PC1=iris.pca$x[,1],PC2=iris.pca$x[,2],Species=  iris[,5])
dat <- dat[order(dat$Species),]

#PCA plot
mainPlot <- ggplot(dat,aes(x=PC1,y=PC2)) + geom_point(size = 2, aes(color=Species))   
mainPlot

#Prop variance table
Prop <- as.data.frame(summary(iris.pca)[[6]])
PropTable <- round(Prop[2,],3)
 
#Prop variance plot
propPlot <- tableGrob(PropTable,theme = ttheme_default(base_size = 8))
 
grid.arrange(propPlot, mainPlot, ncol=1)
Solution

  • The only changes you need to make to your code are in the grid.arrange() function.

    • I replaced ncol = 1 with nrow = 2
    • as.table = TRUE was added
    • heights = c(1, 3) was added (the relative heights of the rows)
    grid.arrange(propPlot, mainPlot, nrow = 2, as.table = TRUE, heights = c(1, 3))

    This is what you will get:

    enter image description here

    I couldn't have found the solution without this blog post: https://magesblog.com/post/2015-04-14-plotting-tables-alsongside-charts-in-r/