pch in R
This tutorial demonstrates the use of pch in R.
pch in R
The pch abbreviated as plot character is the standard argument used to set the character, which will be plotted in different R functions. The pch also can be defined as the explanatory symbol added to a plot; this explanatory text includes legends, axis labels, or titles.
The pch are the symbols you want to add to a plot that explains a certain thing. Here is the list of pch symbols with their values.
pch = 0 square
pch = 1 circle
pch = 2 point up triangle
pch = 3 plus
pch = 4 cross
pch = 5 diamond
pch = 6 point-down triangle
pch = 7 square cross
pch = 8 star
pch = 9 diamond plus
pch = 10 circle plus
pch = 11 up and down triangles
pch = 12 square plus
pch = 13 circle cross
pch = 14 square and down triangle
pch = 15 filled square
pch = 16 filled circle
pch = 17 point-up filled triangle
pch = 18 filled diamond
pch = 19 solid circle
pch = 20 bullet (smaller circle)
pch = 21 filled circle blue
pch = 22 filled square blue
pch = 23 filled diamond blue
pch = 24 filled triangle point-up blue
pch = 25 filled triangle point down blue
The pch is passed as an argument to the legend; the pch method will include the value from the above list. Let’s try an example for the pch.
#data
set.seed(1234)
delftstack <- data.frame(x=runif(10),y=runif(10),
color=rep(c("lightblue","red"),5),
background=rep(c("red", "lightblue"),5),
shape=rep(c(21,24),5),stringsAsFactors = FALSE)
#plot
plot(delftstack$x,delftstack$y,col=delftstack$color,bg=delftstack$background,pch=delftstack$shape,cex=2)
points(x=0.5,y=0.5,pch=8,col="red",cex=2)
#add a legend, pt.bg is needed to fill in the background of the shape
legend(0.01,0.5,
legend = c(expression("PCH"["Example1"]),
expression("PCH"["Example2"]),
expression("PCH"["Example"])),
pch = c(21,24,8),
col = c("lightblue","red","red"),
pt.bg = c("red","lightblue"),
cex=2)
The code above plots the data from the data frame, and then in legend, it tries to apply some characteristics, which also includes pch. See the output:
Sheeraz is a Doctorate fellow in Computer Science at Northwestern Polytechnical University, Xian, China. He has 7 years of Software Development experience in AI, Web, Database, and Desktop technologies. He writes tutorials in Java, PHP, Python, GoLang, R, etc., to help beginners learn the field of Computer Science.
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