R中輔助y軸上的自定義標籤

Question

如何使用以下代碼在R中的輔助y軸上放置自定義標籤？

library(zoo) 
#--------------random data 
x.Date <- as.Date(paste(2003, 02, c(1, 3, 7, 9, 14), sep = "-")) 
z <- zoo(rnorm(5), x.Date) 
z2 <- zoo(rnorm(5, sd = 0.2), x.Date) 

#--------------create plot 
png(filename = "Google.png", width = 480, height = 480) 

plot(z, type="l", xlab="Year", lt=1, lwd=1, ylab="Google Trend") 
grid(nx = NULL, ny = NULL, col = "lightgray", lty = "dotted", 
    lwd = par("lwd"), equilogs = TRUE) 
par(new=TRUE) 
plot(z2, type="l", ann=FALSE, lt=1, lwd=3, yaxt="n") 
axis(4, ylab="Test") # Here?! 

legend("topright", c("z", "z2"), lty=c(1,1), 
    lwd=c(1,3),col=c("black","black"), 
    box.col="black",bg="white") 

title("Google") 
dev.off() 

標籤「測試」並沒有出現在我的陰謀......

此外，如何覆蓋與Z2和Z線網格線？換句話說，如何將繪製的線條帶到「前面」？

Answer 1

需要mtext這個工作：

library(zoo) 
#--------------random data 
x.Date <- as.Date(paste(2003, 02, c(1, 3, 7, 9, 14), sep = "-")) 
z <- zoo(rnorm(5), x.Date) 
z2 <- zoo(rnorm(5, sd = 0.2), x.Date) 

#--------------create plot 
#png(filename = "Google.png", width = 480, height = 480) 

plot(z, type="l", xlab="Year", lt=1, lwd=1, ylab="Google Trend") 
grid(nx = NULL, ny = NULL, col = "lightgray", lty = "dotted", 
    lwd = par("lwd"), equilogs = TRUE) 
par(new=TRUE) 
plot(z2, type="l", ann=FALSE, lt=1, lwd=3, yaxt="n") 
axis(4) 

#------here is the only part I added 
#you specify the text, location and usually line=2 to place next to 
#the y-axis labels 
mtext('Test', side=4, line=2) 
#-----------------------------------  

legend("topright", c("z", "z2"), lty=c(1,1), 
     lwd=c(1,3),col=c("black","black"), 
     box.col="black",bg="white") 

title("Google") 
#dev.off() 

輸出：

至於針對z和Z2他們不似乎是這裏的網格線後面。