gg_shading_bar {plothelper}

Drawing Barplot with Shading Colors

Description

In ordinary barplot, each bar has only one color. This function aims to draw a barplot whose bars have shading effect. Note: unlike ggplot2::geom_bar, this function can only deals with a vector of frequencies.

Usage

gg_shading_bar(
  v,
  labels = NULL,
  raster = NULL,
  flip = FALSE,
  change_order = "normal",
  equal_scale = FALSE,
  smooth = 15,
  interpolate = TRUE,
  width = 0.8,
  color = NA,
  linetype = 1,
  size = 1,
  modify_raster = TRUE,
  space = "rgb",
  ...
)

Arguments

v

a vector of item frequencies. Negative values are OK.

labels

a vector of item names. Its length should be equal to that of v. If it is NULL, default names will be used. If it is of class numeric or factor, it will be transformed to a character vector.

raster

a list. The length of the list should be equal to that of v. Each element of the list should be a color vector corresponding to a value in v. If it is a vector, it will be automatically transformed to a list. If its length is 1, but the length of v is, say, 3, then it will be automatically repeated for 3 times. Let us suppose v = 5 and raster = list(c("green", "red")). This means the starting side of the bar is green and the far side is red. See examples.

flip

default is FALSE and the bars are vertical. When it is TRUE, the bars are horizontal. Note: when using this function, DO NOT USE ggplot2::coord_flip !

change_order

when it is "normal" (default), the drawing order is the order of v. When it is "big", big values will be drawn first. When it is "small", small values will be drawn first. When it is "rev", the inverse order of v will be used.

equal_scale

default is FALSE. When it is TRUE, a bar will use a certain part of the shading colors according to a global scale. See examples.

smooth

default is 15. The number of shading colors each bar has. The bigger, the better.

interpolate

when it is TRUE (default), it makes the colors smoother.

width

the width of each bar. It should be between 0 and 1.

color

color of the outlines of the bars.

linetype

line type of the outlines of the bars.

size

line width of the outlines of the bars.

modify_raster

if it is TRUE (default), colors will be smoothed using the value of smooth. If raster has enough colors, you can set this to FALSE.

space

the space parameter used by colorRampPalette. It should be "rgb" (default) or "Lab".

...

additional arguments used by ggplot2::coord_flip when flip = TRUE.

Examples

library(ggplot2)
x=c(10, 30, 25, 6)
lab=c("children", "youth", "middle", "aged")
r=list(c("cyan", "red"), c("blue", "yellow"), 
	c("green", "orange"), c("grey", "black"))
#
## (1) change_order
# change_order = "ordinary", the default
p1=gg_shading_bar(v=x, labels=lab)
# change_order = "big"
p2=gg_shading_bar(v=x, labels=lab, change_order="big")
# flip and let the largest on the top
p3=gg_shading_bar(v=x, labels=lab, 
	change_order="small", flip=TRUE)
#
## (2) how to use argument raster
p1=gg_shading_bar(v=x, labels=lab, raster=r)
p2=gg_shading_bar(v=x, labels=lab, raster=c("green","red"))
#
## (3) how to use argument equal_scale
# equal_scale = FALSE
# the far side of each bar is red
gg_shading_bar(c(3, 5), raster=c("green", "red"))
# equal_scale = TRUE
# the far side of the shorter bar 
# is not red. Rather, it is something
#' between red and green
gg_shading_bar(c(3, 5), raster=c("green", "red"), 
	equal_scale=TRUE)