R：Barplot - 如何删除栏

Question

嗨，我是R的新手，我已经制作了一个条形图，下面是代码，但是对于数据集“Control”我没有未加工率的数据，因此有一条线条应该是在图表上（见下图）但没有数据！有没有办法让我摆脱它？我是否需要编辑txt文件中的原始数据表？

    barplot(xtabs(ana$Infiltration ~ ana$Grazing + ana$Burn ),beside = TRUE, col = c( "tan4", "darkgreen"), xlab = "Burn Treatment", names = c( "Control", "Long Rotation", "Burned 1954", "Short Rotation" ) , ylab = "Mean Infiltration Rate (mm/h) " , legend = c( "Grazed", "Ungrazed"), args.legend = list(title = "Graze Treatment", x = "topright", cex = .7), ylim = c(0, 40000)  ) 

Answer 1

选项是将xtabs中的0值替换为缺失值，即NA

tbl <- xtabs(Infiltration ~ Grazing + Burn, data = ana )
is.na(tbl) <- tbl == 0

barplot(tbl,beside = TRUE, 
  col = c( "tan4", "darkgreen"), xlab = "Burn Treatment",
   names = c( "Control", "Long Rotation", "Burned 1954", "Short Rotation" ) , 
   ylab = "Mean Infiltration Rate (mm/h) " , 
   legend = c( "Grazed", "Ungrazed"),
   args.legend = list(title = "Graze Treatment", x = "topright",
             cex = .7), ylim = c(0, 20)  ) 

-output

下面，我们在左侧和右侧没有NA替换的NA更换

数据

set.seed(24)
ana <- data.frame(Infiltration = sample(1:5, 20, replace = TRUE),
               Grazing = sample(c("Grazed", "Ungrazed"), 20, replace = TRUE),
               Burn = sample(c("Control", "Long Rotation", "Burned 1954", "Short Rotation"),
                   20, replace = TRUE), stringsAsFactors = TRUE)