英文:
How to use loops for repetitive code in R
问题
我知道关于这个问题有答案，但它仍然让我感到困惑，因为通常用于更高级的任务，而这是一个非常简单的任务。
我有21个数据框，它们的格式为data_1，data_2，data_3等。它们都具有相同的列标题，只是行中的值不同。我想要将所有数据框的第一列重命名为“ID”。我一直在使用以下方法：
names(data_1)[1] <- "ID"
names(data_2)[1] <- "ID" #等等
如何创建一个循环来自动处理具有这种模式的所有数据框？
我还有一组命名为df_1，df_2，df_3等的数据框。df_1具有一个公共列（ID），我想要与data_1进行内部连接，并重复执行data_2和df_2等操作。我一直在使用以下方法：
result_1 <- inner_join(data_1, df_1, by = "ID")
result_2 <- inner_join(data_2, df_2, by = "ID") #等等
如何循环执行这个操作，而不是重复21次？
英文:
I know there are answers out there for this, but it is still confusing me as it is usually for more advanced tasks, and this is a very simple task.
I have 21 data frames that are in the format data_1 data_2 data_3 etc. They all have the same headings, just with different values in the rows. I want to rename column 1 "ID" for all the data frames. I have been using:
names(data_1)[1] <- "ID"
names(data_2)[1] <- "ID" #etc
How can I make a loop to automatically cycle through all the data frames with that pattern?
I have another set of data frames named df_1 df_2 df_3. This df_1 has a common column (ID) that I would like to make an inner join with data_1, and repeat for data_2 and df_2 etc. I was using:
result_1 <- inner_join(data_1, df_1, by = "ID")
result_2 <- inner_join(data_2, df_2, by = "ID") #etc
How could I also loop this instead of repeating myself 21 times?
答案1
得分: 2
这是一个很好的实践，将数据作为一个容器（即一个列表）。例如，
list1 <- mget(ls(pattern = "data_\\d+"))
list2 <- mget(ls(pattern = 'df_\\d+'))
然后你可以循环处理这两个列表：
purrr::map(list1, list2, ~inner_join(setnames(.x, c('ID', names(.x)[-1])), .y, by= 'ID'))
英文:
It is a good practice to have the data as a container (i.e. a list). For example,
list1 <- mget(ls(pattern = "data_\\d+"))
list2 <- mget(ls(pattern = 'df_\\d+'))
then you could loop over the two:
purrr::map(list1, list2, ~inner_join(setnames(.x, c('ID',names(.x)[-1])), .y, by= 'ID'))
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