如何结合情节和传奇？

Question

我试图将一个图例附加到R中的一个情节.我尝试了以下代码(摘自http://www.harding.edu/fmccown/r/)

# Define cars vector with 5 values
cars <- c(1, 3, 6, 4, 9)

# Define some colors ideal for black & white print
colors <- c("white","grey70","grey90","grey50","black")

# Calculate the percentage for each day, rounded to one 
# decimal place
car_labels <- round(cars/sum(cars) * 100, 1)

# Concatenate a '%' char after each value
car_labels <- paste(car_labels, "%", sep="")

# Create a pie chart with defined heading and custom colors
# and labels
pie(cars, main="Cars", col=colors, labels=car_labels,
   cex=0.8)

# Create a legend at the right   
legend(1.5, 0.5, c("Mon","Tue","Wed","Thu","Fri"), cex=0.8, 
   fill=colors)

但是,这不能很好地工作.在馅饼(汽车,主要="汽车",col =颜色,标签= car_labels,cex = 0.8)之后,情节显示没有传说:-) .......我在互联网上看到的每个例子在绘图功能之后似乎有传奇功能所以看起来很奇怪..............

当我尝试执行图例功能时,我得到了

图例(1.5,0.5,c("星期一","星期二","星期三","星期四","星期五"),cex = 0.8,+填充=颜色)strwidth错误(图例,单位="用户", cex = cex):plot.new还没有被调用

Answer 1

你离开了坐标系.试试这个

# Create a legend at the right   
legend("topleft", c("Mon","Tue","Wed","Thu","Fri"), cex=0.8, fill=colors)

产生下图:

有关legend不同的展示位置选项,请参阅帮助页面.