使用 if 循环制作用户定义的 ggplot 派生函数并在另一个自定义 function 中调用它们

Question

I have two custom functions that produce a bar or jitter graph. If an object exists, I would like it to produce the bar graph. If an object doesn't exist, I would like the jitter graph to be produced. I think the problem is making the code inside the if loop within a function dynamic so it can be altered to any dataset.

This is what I have so far, I think this will be an easy fix and I may just be missing formatting/syntax etc... (be kind I am new to writing functions in r).

data <- iris

#graph 1 function:
make_bar_graph <- function(data, x, y, xlab = NULL, ylab = NULL, 
                             linewidth = 0.5, colour = NULL, fill = NULL, 
                             stat.colour = "black", 
                             bar.position = "dodge", bar.width = 0.8, bar.colour = "black", 
                             point.position = position_jitterdodge(0.7), point.size = 2,
                             errorbar.position = position_dodge(0.8), errorbar.width = 0.3, errorbar.colour = "black",
                             ...) {
  ggplot(data = data, aes(x = {{x}}, y = {{y}}, fill = {{fill}}, colour = {{colour}})) +
    geom_bar(stat="summary", fun = "mean", position = bar.position, width = bar.width, colour = bar.colour, show.legend = FALSE, inherit.aes=TRUE, ...) +
    geom_hline(yintercept=0) +
    labs(x=xlab, y=ylab) +
    geom_point(position = point.position, size = point.size, show.legend = FALSE, ...) +
    scale_fill_manual(values = c("gray95", "gray85", "gray75", "gray65", "gray55", "gray45")) +
    scale_colour_manual(values=c("#FF5695", "#8E8DFF", "#8CB5FF", "#79DBFF", "#42EFD7", "#79EBAC")) +
    theme(axis.title.x = element_blank())
   
}


#graph 1 example:
make_bar_graph(data, Species, Petal.Width, fill = Species, colour = Species)


#graph2 function
make_jitter_graph <- function(data, x, y, xlab = NULL, ylab = NULL, linewidth = 0.5, size.jitter = 2, colour = NULL, fill = NULL, stat.colour = "black", ...) {
  ggplot(data = data, aes(x = {{x}}, y = {{y}}, fill = {{fill}}, colour = {{colour}})) +
    stat_summary(fun = median, show.legend = FALSE, geom="crossbar", linewidth = linewidth, colour = stat.colour, ...) +
    geom_jitter(show.legend = FALSE, width = 0.25, size = size.jitter, ...) +
    labs(x=xlab, y=ylab)
}

#graph 2 example:
make_jitter_graph(data = data, x = Species, y = Petal.Width, colour = Species, fill = Species)



#How can I make either of these two graphs produced in a loop:
make_graphs <- function(data, x, y, xlab = NULL, ylab = NULL, 
                             linewidth = 0.5, colour = NULL, fill = NULL, 
                             stat.colour = "black", 
                             bar.position = "dodge", bar.width = 0.8, bar.colour = "black", 
                             point.position = position_jitterdodge(0.7), point.size = 2, 
                             errorbar.position = position_dodge(0.8), errorbar.width = 0.3, errorbar.colour = "black", size.jitter = 2,
                             ...){
  if(exists("OBJECT")){
    require(ggpubr)
    make_bar_graph(data = data, x=x, y=y, linewidth = linewidth, colour = colour, fill = fill,
                       stat.colour = stat.colour, bar.position=bar.position,  bar.width=bar.width, bar.colour=bar.colour,
                       point.position=point.position, point.size=point.size, errorbar.position = errorbar.position, errorbar.width = errorbar.width, errorbar.colour = errorbar.colour, ...)
  }else{
    make_jitter_graph(data = data, x=x, y=y, linewidth = linewidth, colour = colour, fill = fill, stat.colour = stat.colour, size.jitter=size.jitter, ...)
  }
}

# Run when OBJECT doesn't exist:
make_graphs(data = data, x = Species, y = Petal.Width, colour = Species, fill = Species)

#Get error: Error in stat_summary(fun = median, show.legend = FALSE, geom = "crossbar", : ℹ Error occurred in the 1st layer. Caused by error in `FUN()`: ! object 'Species' not found

# Run when OBJECT exists
OBJECT <- 4
make_graphs(data = data, x = Species, y = Petal.Width, colour = Species, fill = Species)

#Get the error: Error in geom_bar(stat = "summary", fun = "mean", position = bar.position, : ℹ Error occurred in the 1st layer. Caused by error in `FUN()`: ! object 'Species' not found

Thank you!

Answer 1

EDIT - two ways to do this:

1) Putting calls to ggplot2 inside make_graphs()

I think there's probably a way to make the whole process more concise, but could you just eliminate the first two functions entirely and put the ggplot calls inside your make_graphs function? Like this

make_graphs <- function(data, x, y, xlab = NULL, ylab = NULL, 
                        linewidth = 0.5, colour = NULL, fill = NULL, 
                        stat.colour = "black", 
                        bar.position = "dodge", bar.width = 0.8, bar.colour = "black", 
                        point.position = position_jitterdodge(0.7), point.size = 2, 
                        errorbar.position = position_dodge(0.8), errorbar.width = 0.3, errorbar.colour = "black", size.jitter = 2,
                        ...){
  if(exists("OBJECT")){
    require(ggpubr)
    ggplot(data = data, aes(x = {{x}}, y = {{y}}, fill = {{fill}}, 
                            colour = {{colour}})) +
      geom_bar(stat="summary", fun = "mean", position = bar.position, 
               width = bar.width, colour = bar.colour, show.legend = FALSE, 
               inherit.aes=TRUE, ...) +
      geom_hline(yintercept=0) +
      labs(x=xlab, y=ylab) +
      geom_point(position = point.position, size = point.size, 
                 show.legend = FALSE, ...) +
      scale_fill_manual(values = c("gray95", "gray85", "gray75", "gray65", 
                                   "gray55", "gray45")) +
      scale_colour_manual(values=c("#FF5695", "#8E8DFF", "#8CB5FF", "#79DBFF", 
                                   "#42EFD7", "#79EBAC")) +
      theme(axis.title.x = element_blank())  }else{
    ggplot(data = data, aes(x = {{x}}, y = {{y}}, fill = {{fill}}, 
                            colour = {{colour}})) +
      stat_summary(fun = median, show.legend = FALSE, geom="crossbar", 
                   linewidth = linewidth, colour = stat.colour, ...) +
      geom_jitter(show.legend = FALSE, width = 0.25, size = size.jitter, ...) +
      labs(x=xlab, y=ylab)  }
}

Then when the object doesn't exist you get this:

rm(OBJECT)
make_graphs(data = data, x = Species, y = Petal.Width, 
            colour = Species, fill = Species)

And when it does exist you get this:

OBJECT <- 4
make_graphs(data = data, x = Species, y = Petal.Width, 
            colour = Species, fill = Species)

2) Using aes_string()

Here, you'd change the way you set up the ggplot functions, so they get their aes() passed as aes_string() instead, then put actual strings in the make_graphs() call. The graph functions get defined like this now:

make_bar_graph <- function(data, x, y, xlab = NULL, ylab = NULL, 
                           linewidth = 0.5, colour = NULL, fill = NULL, 
                           stat.colour = "black", 
                           bar.position = "dodge", bar.width = 0.8, bar.colour = "black", 
                           point.position = position_jitterdodge(0.7), point.size = 2,
                           errorbar.position = position_dodge(0.8), errorbar.width = 0.3, errorbar.colour = "black",
                           ...) {
  ggplot(data = data, aes_string(x = x, y = y, fill = fill, colour = colour)) +
    geom_bar(stat="summary", fun = "mean", position = bar.position, width = bar.width, colour = bar.colour, show.legend = FALSE, inherit.aes=TRUE, ...) +
    geom_hline(yintercept=0) +
    labs(x=xlab, y=ylab) +
    geom_point(position = point.position, size = point.size, show.legend = FALSE, ...) +
    scale_fill_manual(values = c("gray95", "gray85", "gray75", "gray65", "gray55", "gray45")) +
    scale_colour_manual(values=c("#FF5695", "#8E8DFF", "#8CB5FF", "#79DBFF", "#42EFD7", "#79EBAC")) +
    theme(axis.title.x = element_blank())
  
}

make_jitter_graph <- function(data, x, y, xlab = NULL, ylab = NULL, linewidth = 0.5, 
                              size.jitter = 2, colour = NULL, fill = NULL, 
                              stat.colour = "black", ...) {
  ggplot(data = data, aes_string(x = x, y = y, fill = fill, colour = colour)) +
    stat_summary(fun = median, show.legend = FALSE, geom="crossbar", linewidth = linewidth, colour = stat.colour, ...) +
    geom_jitter(show.legend = FALSE, width = 0.25, size = size.jitter, ...) +
    labs(x=xlab, y=ylab)
}

The make_graphs() stay like you had it, then you can just call it like this:

make_graphs(data = data, x = "Species", y = "Petal.Width", 
            colour = "Species", fill = "Species")