錯誤中的R

Question

在數據幀創建新的列我有一個DF，如下所示：

 id type start end features 
1  5 word  1 2  NN 
2  6 word  3 3  . 
3  7 word  5 12  NN 
4  8 word 14 19  VBZ 
5  9 word 21 30  NN 
6 10 word 32 32  WDT 
7 11 word 34 37  VBP 
8 12 word 39 41  IN 
9 13 word 43 44  IN 
10 14 word 46 46  DT 

我想創建一個新的列「總和」與「開始」和「結束」的每個值的總和。

我創建了以下功能：

mySum <- function(row) { 
     row["start"]+row["end"] 
    } 
    df$sum <- apply(df,1, mySum); 

但是當我運行此我得到以下錯誤：

Error in row["start"] + row["end"] : 
    non-numeric argument to binary operator 

但如果我只保留行[「開始」]或行[」結束「]，它會被創建。

我也試圖強制列中的每個值都是數字。

df$start = as.integer(as.vector(df$start)); 
df$end = as.integer(as.vector(df$end)); 

但我仍然得到相同的錯誤，只有當我添加的值。

我的數據幀的結構如下： 後，我跑了dput(droplevels(head(df,10)))

structure(list(id = 5:14, type = c("word", "word", "word", "word", 
"word", "word", "word", "word", "word", "word"), start = c(1L, 
3L, 5L, 14L, 21L, 32L, 34L, 39L, 43L, 46L), end = c(2L, 3L, 12L, 
19L, 30L, 32L, 37L, 41L, 44L, 46L), features = list(structure(list(
    POS = "NN"), .Names = "POS"), structure(list(POS = "."), .Names = "POS"), 
    structure(list(POS = "NN"), .Names = "POS"), structure(list(
     POS = "VBZ"), .Names = "POS"), structure(list(POS = "NN"), .Names = "POS"), 
    structure(list(POS = "WDT"), .Names = "POS"), structure(list(
     POS = "VBP"), .Names = "POS"), structure(list(POS = "IN"), .Names = "POS"), 
    structure(list(POS = "IN"), .Names = "POS"), structure(list(
     POS = "DT"), .Names = "POS"))), .Names = c("id", "type", 
"start", "end", "features"), row.names = c(NA, 10L), class = "data.frame") 

Answer 1

只是做

df1$Sum <- df1[,'start']+ df1[,'end'] 
df1$Sum 
#[1] 3 6 17 33 51 64 71 80 87 92 

或者

rowSums(df1[c('start', 'end')], na.rm=TRUE) 
#1 2 3 4 5 6 7 8 9 10 
#3 6 17 33 51 64 71 80 87 92 

的error建議您有非數字列。檢查str(df1)。如果班級是factor或character，那麼將其更改爲numeric，並應用上述代碼。例如，如果列factor，我們轉換爲numeric由

df1[c('start', 'end')] <- lapply(df1[c('start', 'end')], 
       function(x) as.numeric(as.character(x))) 

在character列的情況下，只需使用as.numeric。