#' Function wraps ggplot2 geom_bar and geom_col to creates a bar plot.
#'
#' Function creates a ggplot2 based bar plot with optional scaling and ordering.
#'
#' @param df The target data frame for the bar chart.
#' @param aes_x Sets the x axis discrete variable name from \code{df}. This variable must be a factor
#' and is required..
#' @param aes_y Sets the y axis numeric variable name from \code{df}. If this variable is NULL
#' the bar heights will be proportional to the number of cases in the levels of \code{aes_x}.
#' If \code{aes_y} is not NULL, the bar heights represent this parameter's values across the \code{aes_x} levels.
#' @param aes_color Sets the variable name from \code{df} for the aesthetic mapping for color.
#' @param aes_fill Sets the variable name from \code{df} for the aesthetic mapping for fill.
#' @param position A string that sets the bar positions. Acceptable values are \code{dodge}(side by side),
#' \code{identity}(overlap) or \code{stack}.
#' @param title A string that sets the overall title.
#' @param subtitle A string that sets the overall subtitle.
#' @param caption A string that sets the captiion.
#' @param center_titles A logical which if \code{TRUE} centers both the \code{title} and \code{subtitle}.
#' @param x_title A string that sets the x axis title. If NULL (the default) then the x axis title does not appear.
#' @param y_title A string that sets the y axis title. If NULL (the default) then the y axis title does not appear.
#' @param hide_x_tics A logical that controls the appearance of the x axis tics.
#' @param hide_y_tics A logical that controls the appearance of the y axis tics.
#' @param rot_x_tic_angle A numeric that sets the angle of rotation for the x tic label. When x tic labels are long,
#' a value of 40 for this argument usually works well.
#' @param rot_y_tic_label A logical which if TRUE rotates the y tic labels 90 degrees for enhanced readability.
#' @param bar_fill A string that sets the fill color attribute for the bars.
#' @param bar_color A string that sets the outline color attribute for the bars.
#' @param bar_alpha A numeric that sets the alpha component attribute to \code{bar_color}.
#' @param bar_size A numeric that sets the outline thickness attribute of the bars.
#' @param bar_width A numeric that sets the width attribute of the bars.
#' @param x_major_breaks If \code{aes_x} is numeric then this parameter is a numeric vector that defines the major
#' breaks/intervals for the x axis. Interval labels are created and their respective counts are displayed.
#' @param y_limits A numeric 2 element vector that sets the minimum and maximum for the y axis.
#' Use NA to refer to the existing minimum and maximum.
#' @param y_major_breaks A numeric vector or function that defines the exact major tic locations along the y axis.
#' @param y_minor_breaks A numeric vector or function that defines the exact minor tic locations along the y axis.
#' @param y_labels A character vector with the same length as \code{y_major_breaks}, that labels the major tics.
#' @param axis_text_size A numeric that sets the font size along the axis'. Default is 11.
#' @param do_coord_flip A logical which if \code{TRUE} will flip the x and y axis'.
#' @param order_bars A string which will order the bars in a specific direction. Acceptable values are "asc" or "desc"
#' @param bar_labels A logical which if \code{TRUE} will label each bar with its value.
#' @param bar_label_sz A numeric that sets the size of the label.
#' @param bar_label_color A string that sets the label's color.
#' @param bar_label_fontface A string that sets the label's font face. Acceptable values are "plain", "bold",
#' "italic", "bold.italic".
#' @param bar_label_alpha A numeric that sets the label's alpha value.
#' @param show_major_grids A logical that controls the appearance of major grids.
#' @param show_minor_grids A logical that controls the appearance of minor grids.
#' @param panel_color A string in hexidecimal or color name that sets the plot panel's color.
#' The default is "white".
#' @param panel_border_color A string in hexidecimal or color name that sets the plot panel's border color.
#' The default is "black".
#' @param show_legend A logical that controls the appearance of the legend.
#' @param legend_pos A string that sets the legend position. Acceptable values are
#' "top", "bottom", "left", "right".
#' @param legend_key_width A numeric that sets the legend width in cm.
#' @param legend_key_height A numeric that sets the legend height in cm.
#' @param legend_key_backgrd A string that sets the legend's background color.
#' @param silent_NA_warning A logical that controls the appearance of a console warning when Na's
#' are removed.
#' @param png_file_path A character string with the directory and file name to produce
#' a png image of the plot.
#' @param png_width_height A numeric vector that sets the width and height of the png image in pixels. The
#' default is c(480,480). There are 37.8 pixels in a centimeter.
#'
#' @importFrom data.table as.data.table
#' @importFrom data.table setorderv
#' @importFrom rlang sym
#' @import ggplot2
#'
#' @return A plot object.
#'
#' @author Rick Dean
#'
#' @export
create_bar_plot <- function(
df,
aes_x = NULL,
aes_y = NULL,
aes_color = NULL,
aes_fill = NULL,
position = "stack",
title = NULL,
subtitle = NULL,
caption = NULL,
center_titles = FALSE,
x_title = NULL,
y_title = NULL,
hide_x_tics = FALSE,
hide_y_tics = FALSE,
rot_x_tic_angle = 0,
rot_y_tic_label = FALSE,
bar_fill = NA,
bar_color = "black",
bar_alpha = 1.0,
bar_size = 1.0,
bar_width = NULL,
x_major_breaks = NULL,
y_limits = NULL,
y_major_breaks = waiver(),
y_minor_breaks = waiver(),
y_labels = waiver(),
axis_text_size = 11,
do_coord_flip = FALSE,
order_bars = NULL,
bar_labels = FALSE,
bar_label_sz = 4,
bar_label_color = "black",
bar_label_fontface = "plain",
bar_label_alpha = 1.0,
show_major_grids = TRUE,
show_minor_grids = TRUE,
panel_color = "white",
panel_border_color = "black",
show_legend = TRUE,
legend_pos = "right",
legend_key_width = 0.7,
legend_key_height = 0.7,
legend_key_backgrd = "white",
silent_NA_warning = FALSE,
png_file_path = NULL,
png_width_height = c(480,480)) {
if(is.null(aes_x)){
stop("aes_x is a required argument.")
}
if(!is.null(aes_fill)){
aes_fill <- rlang::sym(aes_fill)
}
if(!is.null(aes_color)){
aes_color <- rlang::sym(aes_color)
}
# -------------Set geom attribute default values------------------
ggplot2::update_geom_defaults(
"bar",
list(
fill = bar_fill,
color = bar_color,
size = bar_size,
alpha = bar_alpha
)
)
ggplot2::update_geom_defaults(
"col",
list(
fill = bar_fill,
color = bar_color,
size = bar_size,
alpha = bar_alpha
)
)
ggplot2::update_geom_defaults(
"text",
list(
size = bar_label_sz,
color = bar_label_color,
fontface = bar_label_fontface,
alpha = bar_label_alpha
)
)
# Convert df to a data.table
dt <- data.table::as.data.table(df)
# ------------Reorder the data.frame aes_x factor levels?--------------
if(!is.null(order_bars) & is.null(aes_y) & is.null(x_major_breaks)){
# We are doing bars that reflect counts
# 1. Group by aes_x to find the counts for each subgroups N
# 2. Order by the N counts
# 3. Sets the levels of aes_x by this ordering
aes_count_ordered_dt <- NULL
if(order_bars == "desc"){
aes_count_ordered_dt <- dt[, .(N = .N), by = aes_x][order(-N)]
}else{
aes_count_ordered_dt <- dt[, .(N = .N), by = aes_x][order(N)]
}
dt[[aes_x]] <- factor(dt[[aes_x]], levels = aes_count_ordered_dt[[aes_x]])
}else if(!is.null(order_bars) & is.null(x_major_breaks)){
# We are doing bars that reflect values
# 1. Set the order of dt by aes_y
# 2. Set the levels of aes_x by the re-ordered aes_x
if(order_bars == "desc"){
data.table::setorderv(dt, cols = aes_y, order = -1L)
}else {
data.table::setorderv(dt, cols = aes_y, order = 1L)
}
dt[[aes_x]] <- factor(dt[[aes_x]], levels = dt[[aes_x]])
}
# Is x_major_breaks defined?
if(!is.null(x_major_breaks)){
breaks_data_v <- dt[, ..aes_x][[1]]
dt[, cut := cut(x = breaks_data_v, breaks = x_major_breaks, ordered_result = T)]
aes_x <- "cut"
}
# ------------Define the main ggplot2 plot object, aesthetics, geoms------------
aplot <- ggplot(
data = dt
)
if(is.null(aes_y)){ # We are doing counts (i.e. geom_bar)
aplot <- aplot +
geom_bar(
aes(
!!sym(aes_x),
fill = !!aes_fill,
color = !!aes_color
),
stat = "count",
position = position,
width = bar_width,
na.rm = silent_NA_warning
)
}else { # We are doing values (i.e. geom_col)
aplot <- aplot +
geom_col(
aes(
!!sym(aes_x),
!!sym(aes_y),
fill = !!aes_fill,
color = !!aes_color
),
position = position,
width = bar_width,
na.rm = silent_NA_warning
)
}
# -------------------Additional ggplot2 components------------------------
# ----------------------title and subtitle-----------------
if(center_titles) {
aplot <- aplot +
theme(
plot.title = element_text(hjust = .5, size = 20),
plot.subtitle = element_text(hjust = .5, size = 14)
)
}else {
aplot <- aplot +
theme(
plot.title = element_text(size = 20),
plot.subtitle = element_text(size = 14)
)
}
aplot <- aplot + labs(title = title, subtitle = subtitle, caption = caption)
# --------------------panel and grids---------------------
aplot <- aplot +
theme(
panel.background = element_rect(fill = panel_color, color = panel_border_color, size = 2)
)
if(show_major_grids){
aplot <- aplot +
theme(
panel.grid.major = element_line(size = 0.5, linetype = "solid", color = "gray")
)
}
if(show_minor_grids){
aplot <- aplot +
theme(
panel.grid.minor = element_line(size = 0.5, linetype = "solid", color = "gray")
)
}
# ------------------Are we flipping the bars?---------------------
if(do_coord_flip){
aplot <- aplot + coord_flip()
}
# -------------------Are we labeling the bars--------------------
if(bar_labels){
hjust <- 0.0
vjust <- -0.3
if(do_coord_flip){
hjust <- -0.1
vjust <- 0.0
}
if(is.null(aes_y)){
aplot <- aplot +
ggplot2::geom_text(
aes(
!!sym(aes_x),
label = after_stat(count),
hjust = hjust,
vjust = vjust
),
stat = "count",
na.rm = silent_NA_warning
)
}else {
aplot <- aplot +
ggplot2::geom_text(
data = dt,
stat = "identity",
aes(
!!sym(aes_x),
!!sym(aes_y),
label = !!sym(aes_y),
hjust = hjust,
vjust = vjust
)
)
}
}
# ---------------y axis scaling-------------------
aplot <- aplot + scale_y_continuous(
limits = y_limits,
breaks = y_major_breaks,
minor_breaks = y_minor_breaks,
labels = y_labels
)
# x/y tic label size, color, rotation
if(rot_y_tic_label){
rot_y_tic_angle <- 0
}else{
rot_y_tic_angle <- 90
}
aplot <- aplot +
theme(
axis.text.x = element_text(size = axis_text_size, color = "black"),
axis.title.x = element_text(size = axis_text_size + 2, color = "black"),
axis.text.y = element_text(size = axis_text_size, color = "black", angle = rot_y_tic_angle),
axis.title.y = element_text(size = axis_text_size + 2, color = "black")
)
if(rot_x_tic_angle > 0){
aplot <- aplot +
theme(axis.text.x = element_text(angle = rot_x_tic_angle, hjust = 1.0))
}
# --------------------x/y axis titles----------------------------
if(is.null(x_title)) {
aplot <- aplot +
theme(
axis.title.x = element_blank()
)
}else{
aplot <- aplot +
labs(x = x_title)
}
if(is.null(y_title)) {
aplot <- aplot +
theme(
axis.title.y = element_blank()
)
}else{
aplot <- aplot +
labs(y = y_title)
}
# -----------------------hide x/y axis tics?----------------------
if(hide_x_tics){
aplot <- aplot +
theme(
axis.text.x = element_blank(),
axis.ticks.x = element_blank()
)
}
if(hide_y_tics){
aplot <- aplot +
theme(
axis.text.y = element_blank(),
axis.ticks.y = element_blank()
)
}
# -------------------legend related parameters---------------------------
if(!show_legend){
aplot <- aplot +
theme(legend.position = "none")
}else {
aplot <- aplot +
theme(
legend.position = legend_pos,
legend.key = element_rect(fill = legend_key_backgrd),
legend.key.width = unit(legend_key_width, "cm"),
legend.key.height = unit(legend_key_height, "cm")
)
}
# -----------------save the plot as a png file?------------------
if(!is.null(png_file_path)){
grDevices::png(
filename = png_file_path,
width = png_width_height[[1]],
height = png_width_height[[2]]
)
print(aplot)
grDevices::dev.off()
}
return(aplot)
}
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