# f(x) = 3/2 log(x/2) − 2 fuggvenytrafoval 4 lepesben
# (0,4] intervallumon
# 1. log(x) 2. log(x/2) 3. 3/2 log(x/2) 4. f(x)
x <- seq(0,4,0.2)
y1 <- log(x)
y2 <- log(x/2)
y3 <- 3/2 * y2
# vagy: y3 <- 3/2 * log(x/2)
y4 <- y3 - 2
# vagy y4 <- 3/2*log(x/2) -2
plot(x,y1,type="l",ylim=c(-6,1.5),
	ylab="y",main="Függvénytranszformáció")
lines(x,y2,col="blue",lty=3)
lines(x,y3,col="purple")
lines(x,y4,col="red",pch=2,type="o")
legend(2,-4,c("log(x)","log(x/2)",
	"3/2 log(x/2)","3/2log(x/2)-2"),
	col=c("black","blue","purple","red"),
	lty=c(1,3,1,1),
	pch=c(NA,NA,NA,2)
)