R/multi_plot.R

In skylics/stock_analysis: Predict how price of specific financial asset will change.

#' Create multi ggplot graphes (code origin - http://www.cookbook-r.com/Graphs)
#'
#' @param ...
#' @param plotlist
#' @param file
#' @param cols
#' @param layout
#'
#' @return a multiplot
#' @export
multi_plot <- function(..., plotlist = NULL, file, cols = 1, layout = NULL) {

  library(grid, quietly = TRUE)

  # Make a list from the ... arguments and plotlist
  plots <- c(list(...), plotlist)
  numPlots <- length(plots)

  # If layout is NULL, then use 'cols' to determine layout
  if (is.null(layout)) {
    # Make the panel
    # ncol: Number of columns of plots
    # nrow: Number of rows needed, calculated from # of cols
    layout <- matrix(seq(1, cols * ceiling(numPlots/cols)),
                     ncol = cols, nrow = ceiling(numPlots/cols))
  }

  if (numPlots == 1) {
    print(plots[[1]])

  } else {
    # Set up the page
    grid.newpage()
    pushViewport(viewport(layout = grid.layout(nrow(layout), ncol(layout))))

    # Make each plot, in the correct location
    for (i in 1:numPlots) {
      # Get the i,j matrix positions of the regions that contain this subplot
      matchidx <- as.data.frame(which(layout == i, arr.ind = TRUE))

      print(plots[[i]], vp = viewport(layout.pos.row = matchidx$row,
                                      layout.pos.col = matchidx$col))
    }
  }
}