R creating a function with a graph

July 16, 2022

I have a code creates plots that works:

 library(ggplot2)
    x <- Data$V7[c(TRUE, FALSE)]
    y <- Data$V8[c(TRUE, FALSE)]
    
        x <- x[-1]
        y = y[-1]
        df <- data.frame(x = as.numeric(sub(',', '.', x)), y = as.numeric(sub(',', '.', y)))
        
        df$V6 <- factor(df$V6)
        ggplot (df, aes (x, y)) + 
          geom_point(aes(color = V6, shape = V6)) + 
          xlab ("x") + 
          ylab ("y") + 
          geom_abline(slope = 1, linetype = 2, color = "black") +
          facet_wrap(vars(V6)) + 
          theme_bw()

I would like to convert it into a function that, in addition to what in the code above, saves charts in the form of a pdf file.

I don’t really know how to do it, especially with adding a pdf file creation, so please help me.

>Solution :

Something like this?

library(ggplot2)

funPlot <- function(Data, filename) {
  x <- Data$V7[c(TRUE, FALSE)]
  y <- Data$V8[c(TRUE, FALSE)]
  
  x <- x[-1]
  y = y[-1]
  df <- data.frame(x = as.numeric(sub(',', '.', x)), y = as.numeric(sub(',', '.', y)))
  
  df$V6 <- factor(df$V6)
  p <- ggplot (df, aes (x, y)) + 
    geom_point(aes(color = V6, shape = V6)) + 
    xlab ("x") + 
    ylab ("y") + 
    geom_abline(slope = 1, linetype = 2, color = "black") +
    facet_wrap(vars(V6)) + 
    theme_bw()
  
  pdf(filename)
  plot(p)
  dev.off()
  p
}