ggSankeyGrad: ggplot Sankey with color gradient within flows

In ssp3nc3r/ggSankeyGrad: A ggplot-based Sankey Graphic with Gradient Flows

ggplot Sankey with color gradient within flows

Description

ssSankeyGrad returns a ggplot object encoding the flow between beginning and ending categorical data, i.e., a sankey diagram, wherein each flow is encoded as a color gradient. Those color gradients transition between a user-specified color for each category. The parameters are constructed such that c1, c2, col1, col2, and values are all vectors of the same length and corresponding positions represent one flow between categories. The categories c1, c2 are vectors of type character string, col1, col2 are vectors of type character string and include either named colors or hexidecimal representations of color, and values are of an integer or numeric type that encode the amount of "flow" between each category.

The parameter padding adds space between flow categories. color_steps specifies the number of transition colors between categories within each flow. Finally, if label is TRUE, then parameters label_fontface, label_size, and label_color enable label customization.

Usage

ggSankeyGrad(c1, c2, col1 = "gray", col2 = "gray", values,
padding = 2, alpha = 0.4, label = FALSE, label_color = TRUE,
label_fontface = 'bold', label_size = 10, color_steps = 100)

Arguments

c1	Categories that begin each flow.
c2	Categories that end each flow.
col1	Color encoding for beginning categories.
col2	Color encoding for ending categories.
values	Number of items flowing from each beginning to ending category.
padding	Space between categories.
alpha	Transparency of each flow.
label	Whether to include category labels.
label_fontface	Font face used for the labels.
label_color	Font color used for the labels.
label_size	Point size used for the labels.
color_steps	The number of colors used between the beginning and end of the flow.

Examples

# Example 1 with made up data
c1     <- c("A", "A", "B", "B")
c2     <- c("C", "D", "C", "D")
values <- c(2L, 5L, 8L, 3L)
col1   <- c("red", "red", "green", "green")
col2   <- c("blue", "orange", "blue", "orange")

ggSankeyGrad(c1, c2, col1, col2, values, label = TRUE)

# Example 2, data from Nobels, no prizes

d5 <- read.csv(text = '
"Category","University","n","col1","col2"
"Chemistry","Berkeley",5,"#cc5b47","#003262"
"Chemistry","Caltech",4,"#cc5b47","#FF6C0C"
"Chemistry","Cambridge",3,"#cc5b47","#A3C1AD"
"Chemistry","Columbia",3,"#cc5b47","#B9D9EB"
"Chemistry","Harvard",7,"#cc5b47","#A51C30"
"Chemistry","MIT",2,"#cc5b47","#8A8B8C"
"Chemistry","Stanford",7,"#cc5b47","#B1040E"
"Economics","Berkeley",5,"#488595","#003262"
"Economics","Cambridge",3,"#488595","#A3C1AD"
"Economics","Columbia",4,"#488595","#B9D9EB"
"Economics","Harvard",7,"#488595","#A51C30"
"Economics","MIT",5,"#488595","#8A8B8C"
"Economics","Stanford",2,"#488595","#B1040E"
"Literature",NA,0,"#96c17c",NA
"Medicine","Berkeley",2,"#decd7c","#003262"
"Medicine","Caltech",5,"#decd7c","#FF6C0C"
"Medicine","Cambridge",4,"#decd7c","#A3C1AD"
"Medicine","Columbia",4,"#decd7c","#B9D9EB"
"Medicine","Harvard",12,"#decd7c","#A51C30"
"Medicine","MIT",5,"#decd7c","#8A8B8C"
"Medicine","Stanford",3,"#decd7c","#B1040E"
"Peace","Caltech",1,"#924855","#FF6C0C"
"Peace","Columbia",1,"#924855","#B9D9EB"
"Peace","Harvard",1,"#924855","#A51C30"
"Physics","Berkeley",8,"#e79275","#003262"
"Physics","Caltech",7,"#e79275","#FF6C0C"
"Physics","Cambridge",7,"#e79275","#A3C1AD"
"Physics","Columbia",6,"#e79275","#B9D9EB"
"Physics","Harvard",9,"#e79275","#A51C30"
"Physics","MIT",7,"#e79275","#8A8B8C"
"Physics","Stanford",10,"#e79275","#B1040E"
', stringsAsFactors = FALSE)

with(d5, ggSankeyGrad(c1 = Category,
                        c2 = University,
                        col1 = col1,
                        col2 = col2,
                        values = n,
                        label = TRUE))

ssp3nc3r/ggSankeyGrad documentation built on Oct. 11, 2024, 7:06 a.m.