如何摆脱 R 中具有相同名称的多个列？

Question

I'm gathering SAT scores by school districts in Texas and their amount of education spending. The data for SAT scores come in csv files that are split by year. I want to consolidate the scores into my dataframe that has the amount of education spending without creating multiple columns for Total, Math score, Reading score, etc.

I've tried the different types of join functions, semi_join , full_join , left_join , etc. but none of these seems to address the issue I am having.

temp1<-left_join(temp, sat17, by= c("District","year"))%>% 

left_join(., sat16, by=c("District","year"))%>%

left_join(., sat15, by=c("District","year"))%>%

left_join(., sat14, by=c("District","year"))%>%

left_join(., sat13, by=c("District","year"))%>%

left_join(., sat12, by=c("District","year"))%>%

left_join(., sat11, by=c("District","year"))

The output gives me columns Math.x, Math.y, Total.x, Total.y, and so on for each joined dataframe. Also, sat17 includes a column called ERW, instead of Reading because the test changed that year. I want to keep ERW separate, and the rest of the Reading, Math, and Total scores to line up under one of each column.

Answer 1

I think that what you want to do is to bind them together... that is to "add" them up one on the top of the other.

Try:

do.call(rbind, dfs) # dfs is the list of dataframes

or using purrr

library(purrr)
bind_rows(dfs, .id = NULL)

Answer 2

Or say you want to just bind them at the.csv level to begin with, just throw all your files into a subdirectory called "data". You can try something like this:

setwd("./data/")
library(purrr)
library(tidyverse)
binded_data <- tibble(filenames = list.files()) %>%
  mutate(yearly_sat = map(filenames, read_csv)) %>%
  unnest()

Answer 3

Explanation

dplyr is automatically going to rename any columns that you don't join by and have a matching column name in the joined data set.

In your case, since you only want to join by=c("District", "year") , any other columns that have the same name will get renamed.

The starting data set columns getting .x appended to the end of their name, while the columns being left joined get .y appended to the end of their name.

Solution

If you want to have Math, Reading, and Total all in the same column, then you need to stack the data sets in top of each other with dplyr::bind_rows()

combined_sat <- dplyr::bind_rows(sat17, sat16, sat15, sat14, sat13, sat12,  sat11)