Summary plot function

R/summary_graph.R

@@ -0,0 +1,55 @@
+#' Summary Graph
+#'
+#' Produce a graphical summary of variables from a data frame. Variables are plotted
+#' as box plots, grouped and, if enough variables are provided, coloured and facetted.
+#'
+#' @param data A data frame containing the variables to be plotted.
+#' @param response The response variable to plot.
+#' @param exp_var The explanatory (or grouping) variable to plot.
+#' @param resp_units A string providing units to display on the response variable axis.
+#'
+#' @return A ggplot2 plot
+#' @export
+#'
+#' @examples
+#'
+#' summary_graph(iris, "Petal.Length", "Species", "mm")
+#' summary_graph(npk, "yield", c("N", "P", "K"), "lb/plot")
+#'
+summary_graph <- function(data, response, exp_var, resp_units, alpha = 0.3){
+    # What if data is not present?
+    # What if data is not a data frame?
+    # What if response is misspelt?
+    # What if response is an invalid type?
+    # What if >2 exp_var?
+    #
+
+    if(length(exp_var)==1){
+        gg <- ggplot2::ggplot(data = data, ggplot2::aes(x = .data[[exp_var]], y = .data[[response]])) +
+            ggplot2::geom_boxplot() +
+            ggplot2::geom_point(alpha = alpha) +
+            ggplot2::labs(y = paste(response, " (", resp_units, ")", sep = "")) +
+            ggplot2::theme_bw()
+    }
+    else if(length(exp_var) == 2){
+        gg <- ggplot2::ggplot(data = data, ggplot2::aes(x = .data[[exp_var[1]]], y = .data[[response]],
+                                                        colour = .data[[exp_var[2]]], group = .data[[exp_var[2]]])) +
+            ggplot2::stat_summary(fun = mean, geom = "point") +
+            ggplot2::stat_summary(fun = mean, geom = "line") +
+            ggplot2::geom_point(alpha = alpha) +
+            ggplot2::labs(y = paste(response, " (", resp_units, ")", sep = "")) +
+            ggplot2::theme_bw()
+    }
+    else {
+        gg <- ggplot2::ggplot(data = data, ggplot2::aes(x = .data[[exp_var[1]]], y = .data[[response]],
+                                                        colour = .data[[exp_var[2]]], group = .data[[exp_var[2]]])) +
+            ggplot2::stat_summary(fun = mean, geom = "point") +
+            ggplot2::stat_summary(fun = mean, geom = "line") +
+            ggplot2::facet_wrap(~ .data[[exp_var[3]]]) +
+            ggplot2::geom_point(alpha = alpha) +
+            ggplot2::labs(y = paste(response, " (", resp_units, ")", sep = "")) +
+            ggplot2::theme_bw()
+    }
+
+    return(gg)
+}