Week.07 : 그래픽 구현 Visualization

Table of Contents

그래프 옵션 Graph Option
그래프 종료 Type of Graph

그래픽 구현 Visualization

R에는 기본적으로 그래프 구현 도구를 제공한다. 기본으로 제공하는 패키지 말고도, CRAN에 다른 여러 사람들이 많은 그래픽 패키지가 있지만, 여기서는 가장 기본적인 그래프 구현방법을 알아보도록 한다.

그래프 옵션 Graph Option

이전에 사용했던 강우유출 데이터를 이용하여 그래프를 그려보도록 한다.
6주차의 코드에 이어 다음과 같은 명령어로 그래프를 나타낼 수 있다.

plot(dat[,3], type = "b")

type은 그래프의 형태를 나타내며 속성값은 아래와 같다.
type : what type of plot should be drawn. Possible types are

p : for points,
l : for lines,
b : for both,
c : for the lines part alone of ‘"b"’,
o : for both ‘overplotted’,
h : for ‘histogram’ like (or ‘high-density’) vertical lines,
s : for stair steps,
S : for other Steps, see ‘Details’ below,
n : for no plotting.

그래프 제목 그리고 축 Title of Graph and Axis

plot(dat[,3], type = "b", xlab = "time (hour)", ylab ="outflow (cm)",
main="Hydrograph", sub="sub title")

main : an overall title for the plot
sub : a sub title for the plot
xlab : a title for the x axis
ylab : a title for the y axis

좌표값 및 범위설정 Coordinate Value and Range

plot(dat[,3], type = "b", xlab = "time (hour)", ylab ="outflow (cm)", 
main="Hydrograph", sub="sub title", xlim=c(0,20), ylim=c(-0.5,7))

xlim : range of x axis
ylim : range of y axis

범례 Legend

legend(0, max(dat[,3])+1, "flow", pch=1, lty=1)

0 : x 좌표 위치
max(dat[,3])+1 : y 좌표 위치
"flow" : 그래프 이름
pch=1 : pont character
lty : line type

그래프 배열 Graph Arrangement


par(mfrow=c(1, 2))
plot(dat[,3], type = "b", xlab = "time (hour)", ylab ="outflow (cm)", 
	main="Outflow", xlim=c(0,20), ylim=c(-0.5,max(dat[,2:3])))
legend(0, max(dat[,2:3]), "flow", pch=1, lty=1);
plot(dat[,2], type = "b", xlab = "time (hour)", ylab ="rainfall (cm)", 
	main="Rainfall", xlim=c(0,20), ylim=c(-0.5,max(dat[,2:3])), pch=2, lty=2, col="red")
legend(0, max(dat[,2:3]), "rain", pch=2, lty=2, col="red");

par : 그래픽에 관련된 변수들을 제어한다. mfrow=c(1,2) : 레이아웃을 1행 2열로 나눈다.

여러 축 Mutiple Axis

par(mar=c(5, 5, 5, 5) ) # to give a little more room for constructing the on the four side.
barplot(dat[,2], xlim=c(0,20), ylim=c(max(dat[,2])*3,0), col=c(rgb(0.4,0.7,0.4)), axes=FALSE, ylab="")
axis(2, at=0:max(dat[,2])*3, col=rgb(0.4,0.7,0.4)) # y axis left
par(new=TRUE)
plot(dat[,3], type="l",col="red", ylim=c(0,max(dat[,3])*1.5),axes=FALSE, ylab="", xlab="")
axis(1, at=1:nrow(dat)) # x axis bottom
axis(3, at=1:nrow(dat)) # x axis top
axis(4, at=0:max(dat[,3])*1.5, col="red") # y axis right
mtext(side = 1, line = 3, "Time (hour)")
mtext(side = 2, line = 3, "Rainfall (cm)")
mtext(side = 3, line = 3, "Time (hour)")
mtext(side = 4, line = 3, "Flow (cm)")

그래프 종료 Type of Graph

선 그래프 Line Graph

## set up some fake test data
time <- seq(0,72,12)
betagal.abs <- c(0.05,0.18,0.25,0.31,0.32,0.34,0.35)
cell.density <- seq(0,6000,1000)

## add extra space to right margin of plot within frame
par(mar=c(5, 4, 4, 6) + 0.1)

## Plot first set of data and draw its axis
plot(time, betagal.abs, pch=16, axes=FALSE, ylim=c(0,1), xlab="", ylab="", 
   type="b",col="black", main="Mike's test data")
axis(2, ylim=c(0,1),col="black",las=1)  ## las=1 makes horizontal labels
mtext("Beta Gal Absorbance",side=2,line=2.5)
box()

## Allow a second plot on the same graph
par(new=TRUE)

## Plot the second plot and put axis scale on right
plot(time, cell.density, pch=15,  xlab="", ylab="", ylim=c(0,7000), 
	axes=FALSE, type="b", col="red")
## a little farther out (line=4) to make room for labels
mtext("Cell Density",side=4,col="red",line=4) 
axis(4, ylim=c(0,7000), col="red",col.axis="red",las=1)

## Draw the time axis
axis(1,pretty(range(time),10))
mtext("Time (Hours)",side=1,col="black",line=2.5)  

## Add Legend
legend("topleft",legend=c("Beta Gal","Cell Density"),
text.col=c("black","red"),pch=c(16,15),col=c("black","red"))

산포도 Scatter Plot

##  Set up plotting in two rows and three columns, plotting along rows first.
par(mfrow=c(2, 2))
##  The first plot is located in row 1, column 1:
plot( rnorm(n=10), col = "red", main = "plot 1", cex.lab = 1.1 )
plot( rnorm(n=20), col = "blue", main = "plot 2", cex.lab = 1.2 )
plot( rnorm(n=30), col = "green", main = "plot 4", cex.lab = 1.3 )
plot( rnorm(n=40), col = "yellow", main = "plot 4", cex.lab = 1.4 )

막대 그래프 Barplot

x <- c(3,2,6,8,4)
barplot(x,border="tan2",
names.arg=c("Jan","Feb","Mar","Apr","May"),xlab="Month", ylab="Revenue",density=c(0,5,20,50,100))

상자 그림 Boxplot

data<-data.frame(Stat11=rnorm(100,mean=3,sd=2),
				 Stat21=rnorm(100,mean=4,sd=1),
				 Stat31=rnorm(100,mean=6,sd=0.5),
				 Stat41=rnorm(100,mean=10,sd=0.5),
				 Stat12=rnorm(100,mean=4,sd=2),
				 Stat22=rnorm(100,mean=4.5,sd=2),
				 Stat32=rnorm(100,mean=7,sd=0.5),
				 Stat42=rnorm(100,mean=8,sd=3),
				 Stat13=rnorm(100,mean=6,sd=0.5),
				 Stat23=rnorm(100,mean=5,sd=3),
				 Stat33=rnorm(100,mean=8,sd=0.2),
				 Stat43=rnorm(100,mean=4,sd=4)
				 )

boxplot(data, 
		ylab ="Oxigen (%)", 
		las = 2, 
		col = c("red","sienna","palevioletred1","royalblue2",
			"red","sienna","palevioletred1","royalblue2",
			"red","sienna","palevioletred1","royalblue2"),
		at = c(1,2,3,4, 6,7,8,9, 11,12,13,14), 
		par(mar = c(12, 5, 4, 2) + 0.1), 
		names = c("Station 1","Station 2","Station 3","Station 4",
			"Station 1","Station 2","Station 3","Station 4",
			"Station 1","Station 2","Station 3","Station 4")
)
mtext(side = 1, line = 6, "Time")

Reference

Frank McCown(2007). Producing Simple Graphs with R [Link]
Quick-R. Creating a Graph [Link]
서민구(2013). R을 이용한 데이터 실무. [D own]