Question

我想在我的条形图中找到一个缺少数据的列。

adult <- read.csv(
    "http://archive.ics.uci.edu/ml/machine-learning-databases/adult/adult.data", 
    header = FALSE, 
    na.strings = "?", 
    strip.white = TRUE
)
colnames(adult) <- c("age", "workClass", "fnlwgt", "education", "educationNum", "maritalStatus", "occupation", "relationship", "race", "sex", "capitalGain", "capitalLoss", "hoursPerWeek", "nativeCountry", "prediction")
barplot(table(adult$workClass), main="Job Distribution", xlab="Job", ylab="Count",las=2)

我知道在这个数据集中，workClass有1836个缺失值，来自

length(which(is.na(adult$workClass)))

Answer 1

您可以在useNA = "ifany"中使用参数table。

tab <- table(adult$workClass, useNA = "ifany")
#  Federal-gov        Local-gov     Never-worked          Private 
#          960             2093                7            22696 
# Self-emp-inc Self-emp-not-inc        State-gov      Without-pay 
#         1116             2541             1298               14 
#         <NA> 
#         1836

默认情况下，NA计数的名称为NA。您可以使用以下命令将名称更改为字符串"NA"。

names(tab)[is.na(names(tab))] <- "NA"

现在，图表也在 x 轴上显示名称"NA"。

barplot(tab, main = "Job Distribution", xlab = "Job", ylab = "Count", las = 2)

<na> </na>的barplot列

1 个答案: