CODEWITHSUNDEEP
rtidyverse
user8229029
user8229029

Reputation: 1162

Adding a third column to list of data frames R tidyverse

I have a data frame where the last column ("data") consists of a list of data frames, each of which has a "Year" and a "Yield" column. I want to add a 3rd column, "Det_Yield" to each data frame in the column. I'm wondering how to do this the "tidyverse" way.

enter image description here

I've done it using a loop, like this, but I would like to know how to use map or some other tidy method to do this. Thank you.

   for (cty in 1:66){
       corn_by_county[[3]][[cty]]$Det_Yield <- NA
       yield_model <- lm(corn_by_county[[3]][[cty]]$Yield ~ corn_by_county[[3]][[cty]]$Year)
       corn_by_county[[3]][[cty]]$Det_Yield <- resid(yield_model)}

enter image description here

Upvotes: 0

Views: 99

Answers (1)

rjen
rjen

Reputation: 1972

You can use map in the following way.

library(dplyr)
library(purrr)

viewOutput <- df %>%
  mutate(data = map(data, ~ mutate(.x, det_yield = 'whatever')))

viewOutput$data

# [[1]]
# A tibble: 2 x 3
#    year yield det_yield
#   <dbl> <dbl> <chr>    
# 1  1999     5 whatever 
# 2  2000     6 whatever 

# [[2]]
# A tibble: 2 x 3
#    year yield det_yield
#   <dbl> <dbl> <chr>    
# 1  2001     7 whatever 
# 2  2002     8 whatever

Arbitrary demo data

df <- structure(list(data = list(structure(list(year = c(1999, 2000
), yield = c(5, 6)), row.names = c(NA, -2L), class = c("tbl_df", 
"tbl", "data.frame")), structure(list(year = c(2001, 2002), yield = c(7, 
8)), row.names = c(NA, -2L), class = c("tbl_df", "tbl", "data.frame"
)))), row.names = c(NA, -2L), class = c("tbl_df", "tbl", "data.frame"
))

Upvotes: 1

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