How to further melt a dataset?

问题

I'm working with the following data:

#Reproducible Example
Bills <- c("93-HCONRES-106", "93-HCONRES-107", "93-HCONRES-108")
Members <- c("00134", "00416;00010;00017;00026", "00416;00503;00513;00568")

data <- data.frame(Bills, Members)

Where the data looks like this:

#Data Structure
            Bills                 Members
1 93-HCONRES-106                   00134
2 93-HCONRES-107 00416;00010;00017;00026
3 93-HCONRES-108 00416;00503;00513;00568

What I would like is for the dataset to extend, such that each bill corresponds with each member. So the data looks like this:

        Bills           Members
93-HCONRES-106          00134
93-HCONRES-107          00416
93-HCONRES-107          00010
93-HCONRES-107          00017
93-HCONRES-107          00026
93-HCONRES-108          00416
93-HCONRES-108          00503
93-HCONRES-108          00513
93-HCONRES-108          00568

Any code you could share would be greatly appreciated.

Thanks so much for all your help

回答1:

We can use separate_rows from tidyr

library(dplyr)
library(tidyr)
data %>% 
     separate_rows(Members)
#         Bills Members
#1 93-HCONRES-106   00134
#2 93-HCONRES-107   00416
#3 93-HCONRES-107   00010
#4 93-HCONRES-107   00017
#5 93-HCONRES-107   00026
#6 93-HCONRES-108   00416
#7 93-HCONRES-108   00503
#8 93-HCONRES-108   00513
#9 93-HCONRES-108   00568

Or extract the elements into a list and then unnest

library(stringr)
data %>%
   mutate(Members = str_extract_all(Members, "[^;]+")) %>% 
   unnest(c(Members))

Or with base R

stack(setNames(strsplit(as.character(data$Members), ";"), data$Bills))

回答2:

Using data.table:

library(data.table)
dt1 <- data.table(Bills, Members)
dt2 <- melt(dt1[, c("V1", "V2", "V3", "V4") := tstrsplit(Members, ";")][, Members := NULL], id.vars = "Bills")[!is.na(value)][order(Bills)]

来源：https://stackoverflow.com/questions/60841927/how-to-further-melt-a-dataset

标签

reshape

data-manipulation

melt