Question

我一直在努力解决以下问题：

我有以下变量：

class(HARdata)
[1] "data.frame"
dim(HARdata)
[1] 10299    88

class(activity_labels)
[1] "character"
length(activity_labels)
[1] 6

我一直试图运行以下循环：

for (i in 1:nrow(HARdata)) { 
  for (j in 1:length(activity_labels)){
    if (as.numeric(HARdata[i, "traintype"]) == extract_numeric(activity_labels[j])) {
      HARdata[i, "traintype"] <- activity_labels[j]
    }
  }
}

但是，我收到以下错误：

Error in if (as.numeric(HARdata[i, "traintype"]) == extract_numeric(activity_labels[j])) { : 
  missing value where TRUE/FALSE needed

另外：警告信息：强制引入的NA

如果我替换HARdata[i, "traintype"] <- activity_labels[j] with HARdata[i, "traintype"] <- 10，代码运行正常。所以我认为问题出在这一行。左侧是数字，而右侧是字符。我试过运行as.character(HARdata[i, "traintype"]) <- "test"，但这不起作用。任何人都可以看到可能出现的问题吗？

Answer 1

test <- scan()
0.27513126 0.39694439
0.54228045 0.82751195
0.18600784 0.96602747
0.55259276 0.52368149
0.28976503 0.74500213
0.17534195 0.04931733
0.08077429 0.82169260
0.72602526 0.94921645
0.65077605 0.06989442
0.81399236 0.1379080

test <- as.data.frame(matrix(test, ncol=2))
names(test) <- c('cartype', 'traintype')

library(tidyr)

activity_labels <- c("$0.08077429", "$0.65077605")
test[,"traintype"][match(extract_numeric(activity_labels), test[,"traintype"])] <- activity_labels

无法转换＆amp;将字符值分配给数字字段

1 个答案: