沿循环中的列移动

以下是您可以进行的一些更改。以下是完整的功能:

rowdiff<-function(df,na.rm=F){
> mrowdiff <- df # you want mrowdiff to have the same basic structure as df, so start with making it equal to df (there are more efficient ways to do this)
> for(i in 1:nrow(df))
+ {
+     mrowdiff[i, ]<-df[i+1, ]-df[i, ] # calculate differences for both rows at once
+     }
> mrowdiff<- na.omit(mrowdiff) # remove missing values
> mrowdiff # there's nothing to rbind, since you've been working with a dataframe all along
  }

rowdiff(df)
   x y
1  0 0
2  4 0
3 -2 0
4  8 0
5 -5 0

这是一种避免使用函数的简单方法,尽管您提到…

for (j in 1:ncol(df)) {
    df[,paste0("rowdiff",j)] <- NA
    for (i in 2:nrow(df)) {
        df[i,paste0("rowdiff",j)] <- df[i,j] - df[i-1,j]
    }   
}

输出:

> df
   x    y rowdiff1 rowdiff2
1  0 1000       NA       NA
2  0 1000        0        0
3  4 1000        4        0
4  2 1000       -2        0
5 10 1000        8        0
6  5 1000       -5        0