Question

我有以下数据集：

dataset

我想查看action_ID列中的ID，并检查它是否在value列中。如果是，我想查看关联变量是否为Comment。如果是Comment，我会将该ID的评论数量加1到一个名为final的新数据框中，该数据框由action_ID和数量组成评价。

这是我到目前为止编写的代码：

final = data.frame(action_ID = c(1001,981,734,985))

for (x in shares$action_ID) {
    if ((x %in% shares$value) & (shares$variable[shares$value == x] =="Comment")){
      final$num_comments[final$action_ID == x] =+ 1
    }else {
       final$num_comments[final$action_ID == x]  =+ 0
   }
}

每当我运行它都不起作用。我试着通过查看if语句中的第一个条件来调试它，但由于某种原因，if语句并没有真正起作用。 action_ID中的每个值都会输出。我也尝试使用任何不起作用的。

for (x in shares$action_ID){
    print(x)
    if (any(shares$value == x)){ # & (shares$variable[shares$value == x]== "Comment")){
        print(x)

    }
}

输出：

[1] "734"
[1] "1001"
[1] "1001"
[1] "985"
[1] "981"

感谢您的帮助!!

编辑：我不认为我对输出非常清楚，我正在尝试创建一个表格，其中包含有0条评论，1条评论，2条评论等的帖子数量。

Answer 1

使用app.use(function(req, res, next) { res.locals.success_msg = req.flash('success_msg'); res.locals.error_msg = req.flash('error_msg'); res.locals.error = req.flash('error'); next(); })解决方案：

tidyverse

输出将是一个数据框，其中新列library(tidyverse) df <- data_frame(action_ID = c(734, 1001, 985, 981), variable = c("Photo", "Post", "Share", "Comment"), value = c(234, 345, 1001, 1001)) # add the cnt variable before hand df$cnt <- c(0) df %>% filter(action_ID == value, variable == "Comment") %>% mutate(cnt = cnt + 1) %>% select(action_ID, cnt)包含所需的值您的示例的问题是您的标准未得到满足。

Answer 2

你正在努力使它比循环更难：

因为听起来您想要按值将评论数量链接回相应的action_ID，所以首先按value计算评论，然后再加入主数据框是有意义的

require(dplyr)

# create some data that mirrors yours

set.seed(1112124)
df <- data.frame(    
    action_ID= seq(1,10),
    variable = sample(c("Photo","Post","Share","Comment"),10,replace=T),
    value = sample(1:10,10,replace=T)
)


# first we tag each row with whether or not it's a comment (1 or 0)
Comments <- df %>% mutate(Comment = ifelse(variable=="Comment",1,0)) %>% 

  # then group by value because we want to summarize at that level
  group_by(value) %>% 
  # then add up the number of comments for each ID
  summarize(N_Comments = sum(Comment))

  # now add our comment counts back to the original action IDs
left_join(df, Comments, by = c("action_ID"="value"))


   action_ID variable value N_Comments
1          1    Photo     5         NA
2          2  Comment     7         NA
3          3     Post     6         NA
4          4  Comment     5         NA
5          5    Share     9          1
6          6  Comment     7          0
7          7     Post    10          2
8          8     Post    10          1
9          9  Comment    10          0
10        10  Comment     8          1

R：如果for循环中的语句似乎不起作用？

2 个答案: