Transforming R Base Plot into a Themed GGplot-CodePudding

I wondered if there exists a simple method for transforming base output in R into a nicer GGplot themed plot (such as theme_ipsum)?

Would appreciate any/all feedback on this given the PCA base plot example below.


install.packages("Gifi")
library(Gifi)

ABC6 <- ABC[,6:11]
fitord <- princals(ABC6)  
plot(fitord)

CodePudding user response：

The ggplot2 function autoplot is an S3 generic that allows users to define a way of creating a ggplot automatically from an object of a particular class. Although the authors of Gifi have written a base R plot method (Gifi:::plot.princals) so that you can do plot(fitord), they haven't written an autoplot.princals method to allow a ggplot to be created. However, it's not terribly difficult to do this yourself:

library(tidyverse)

autoplot.princals <- function(x) {
  x$loadings %>%
    as.data.frame() %>%
    rownames_to_column() %>%
    ggplot(aes(0, 0))  
    geom_segment(aes(xend = D1, yend = D2),
                 arrow = arrow(length = unit(3, "mm")))  
    geom_text(aes(D1, D2   ifelse(D2 > 0, 0.03, -0.03), label = rowname),
              hjust = 0)  
    geom_hline(yintercept = 0, color = "gray", linetype = 2)  
    geom_vline(xintercept = 0, color = "gray", linetype = 2)  
    coord_cartesian(xlim = c(min(c(0.5 * -abs(x$loadings[,1]), x$loadings[,1])),
                             max(c(0.5 * abs(x$loadings[,1]),
                                   1.5 * x$loadings[,1]))))  
    labs(x = "Component 1", y = "Component 2")  
    hrbrthemes::theme_ipsum()
}

Which means we can simply do:

autoplot(fitord)

And, to show this generalizes, we can do

autoplot(princals(mtcars))