通过在因子内粘贴级别来折叠数据

Question

我的数据如下：

proposal_number <- c("Expt 1", "Expt 1", "Expt 1", "Expt 2", "Expt 2")
crop_weight <- c("Winter Wheat 200g", "Winter Barley 200g", "Spring Beans 500g", "Winter Wheat 300g", "Spring Beans 100g")
data<-data.frame(proposal_number, crop_weight)

  proposal_number        crop_weight
1          Expt 1  Winter Wheat 200g
2          Expt 1  Winter Barley 200g
3          Expt 1  Spring Beans 500g
4          Expt 2  Winter Wheat 300g
5          Expt 2  Spring Beans 100g

我想通过crop_weight来降低proposal_number的级别，所以它看起来如下：

  proposal_number                                              crop_weight
1          Expt 1 Winter Wheat 200g, Winter Barley 200g, Spring Beans 500g
2          Expt 2                     Winter Wheat 300g, Spring Beans 100

我已经走了这么远：

help <-data %>% 
  group_by(proposal_number) %>%
  mutate(crop_weight = paste(crop_weight, collapse = "; ")) 

但是，它将所有-- crop_weight的因子级别--用于proposal_number的两个因素级别，如下所示：

 proposal_number                                                                                    crop_weight
1          Expt 1 Winter Wheat 200g, Winter Barley 200g, Spring Beans 500g, Winter Wheat 300g, Spring Beans 100g
2          Expt 2 Winter Wheat 200g, Winter Barley 200g, Spring Beans 500g, Winter Wheat 300g, Spring Beans 100g

我已经搜索了整个上午，也许我的搜索词是错的，但我找不到一个明显的答案。我很感谢你对我哪里出了问题有任何见解吗？

这是我发现的最有用的线索，但正如我上面所说，它不太管用.Concatenate strings by group with dplyr

非常感谢

Answer 1

使用summarise而不是mutate

data %>% 
  group_by(proposal_number) %>% 
  summarise(crop_weight = paste0(crop_weight,collapse = ","))

输出：

  proposal_number crop_weight                                           
  <chr>           <chr>                                                 
1 Expt 1          Winter Wheat 200g,Winter Barley 200g,Spring Beans 500g
2 Expt 2          Winter Wheat 300g,Spring Beans 100g