Combine Multiple Columns Into Tidy Data [duplicate]
My dataset looks like this:
unique.id abx.1 start.1 stop.1 abx.2 start.2 stop.2 abx.3 start.3 stop.3 abx.4 start.4
1 1 Moxi 2014-01-01 2014-01-07 PenG 2014-01-01 2014-01-07 Vanco 2014-01-01 2014-01-07 Moxi 2014-01-01
2 2 Moxi 2014-01-01 2014-01-02 Cipro 2014-01-01 2014-01-02 PenG 2014-01-01 2014-01-02 Vanco 2014-01-01
3 3 Cipro 2014-01-01 2014-01-05 Vanco 2014-01-01 2014-01-05 Cipro 2014-01-01 2014-01-05 Vanco 2014-01-01
4 4 Vanco 2014-01-02 2014-01-03 Cipro 2014-01-02 2014-01-03 Cipro 2014-01-02 2014-01-03 PenG 2014-01-02
5 5 Vanco 2014-01-01 2014-01-02 PenG 2014-01-01 2014-01-02 PenG 2014-01-01 2014-01-02 Cipro 2014-01-01
stop.4 intervention
1 2014-01-07 0
2 2014-01-02 0
3 2014-01-05 1
4 2014-01-03 1
5 2014-01-02 0
With some code to create this:
abxoptions <- c("Cipro", "Moxi", "PenG", "Vanco")
df3 <- data.frame(
unique.id = 1:5,
abx.1 = sample(abxoptions,5, replace=TRUE),
start.1 = as.Date(c('2014-01-01', '2014-01-01', '2014-01-01', '2014-01-02', '2014-01-01')),
stop.1 = as.Date(c('2014-01-07', '2014-01-02', '2014-01-05', '2014-01-03', '2014-01-02')),
abx.2 = sample(abxoptions,5, replace=TRUE),
start.2 = as.Date(c('2014-01-01', '2014-01-01', '2014-01-01', '2014-01-02', '2014-01-01')),
stop.2 = as.Date(c('2014-01-07', '2014-01-02', '2014-01-05', '2014-01-03', '2014-01-02')),
abx.3 = sample(abxoptions,5, replace=TRUE),
start.3 = as.Date(c('2014-01-01', '2014-01-01', '2014-01-01', '2014-01-02', '2014-01-01')),
stop.3 = as.Date(c('2014-01-07', '2014-01-02', '2014-01-05', '2014-01-03', '2014-01-02')),
abx.4 = sample(abxoptions,5, replace=TRUE),
start.4 = as.Date(c('2014-01-01', '2014-01-01', '2014-01-01', '2014-01-02', '2014-01-01')),
stop.4 = as.Date(c('2014-01-07', '2014-01-02', '2014-01-05', '2014-01-03', '2014-01-02')),
intervention = c(0,0,1,1,0)
)
I would like to tidy this data to look like this:
unique.id abx start stop intervention
1 Moxi 2014-01-10 2014-01-07 0
1 Pen G 2014-01-01 2014-01-07 0
1 Vanco 2014-01-01 2014-01-07 0
1 Moxi 2014-01-01 2014-01-07 0 etc etc
The following solutions didn't get me where I needed: Gather multiple sets of columns and Combining multiple columns into one
I suspect that Hadley's amazing tidyr pakcage is the way to go...just can't figure this out. Any help would be greatly appreciated.
Solution 1:
Almost every data tidying problem can be solved in three steps:
- Gather all non-variable columns
- Separate "colname" column into multiple variables
- Re-spread the data
(often you'll only need one or two of these, but I think they're almost always in this order).
For your data:
- The only column that's already a variable is
unique.id
- You need to split current column names into variable and number
- Then you need to put the "variable" variable back into columns
This looks like:
library(tidyr)
library(dplyr)
df3 %>%
gather(col, value, -unique.id, -intervention) %>%
separate(col, c("variable", "number")) %>%
spread(variable, value, convert = TRUE) %>%
mutate(start = as.Date(start, "1970-01-01"), stop = as.Date(stop, "1970-01-01"))
Your case is a bit more complicated because you have two types of variables, so you need to restore the types at the end.
Solution 2:
You could try reshape
from base R
reshape(df3, direction='long', varying=2:ncol(df3), sep=".")
Or use merged.stack
from splitstackshape
library(splitstackshape)
merged.stack(df3, var.stubs=c('abx', 'start', 'stop'), sep='.')[,
c('start', 'stop') := lapply(.SD, as.Date,
origin='1970-01-01'), .SDcols=4:5][]
Solution 3:
Recently, a new feature has been added to melt.data.table
, which allows melting into multiple columns painless. All you've to do is provide the columns you'd want to melt separately in a list
in measure.vars
argument.
You can grab the development version by following these instructions.
require(data.table) ## v1.9.5
setDT(dat) # dat is now a data.table
melt(dat, id = 1L, measure = patterns("^abx", "^start", "^stop"),
value.name = c("abx", "start", "stop"))
# unique.id variable abx start stop
# 1: 1 1 Moxi 2014-01-01 2014-01-07
# 2: 2 1 Moxi 2014-01-01 2014-01-02
# 3: 3 1 Cipro 2014-01-01 2014-01-05
# 4: 4 1 Vanco 2014-01-02 2014-01-03
# 5: 5 1 Vanco 2014-01-01 2014-01-02
# 6: 1 2 PenG 2014-01-01 2014-01-07
# 7: 2 2 Cipro 2014-01-01 2014-01-02
# 8: 3 2 Vanco 2014-01-01 2014-01-05
# 9: 4 2 Cipro 2014-01-02 2014-01-03
# 10: 5 2 PenG 2014-01-01 2014-01-02
# 11: 1 3 Vanco 2014-01-01 2014-01-07
# 12: 2 3 PenG 2014-01-01 2014-01-02
# 13: 3 3 Cipro 2014-01-01 2014-01-05
# 14: 4 3 Cipro 2014-01-02 2014-01-03
# 15: 5 3 PenG 2014-01-01 2014-01-02
# 16: 1 4 Moxi 2014-01-01 2014-01-07
# 17: 2 4 Vanco 2014-01-01 2014-01-02
# 18: 3 4 Vanco 2014-01-01 2014-01-05
# 19: 4 4 PenG 2014-01-02 2014-01-03
# 20: 5 4 Cipro 2014-01-01 2014-01-02
I've used column numbers here, but you can provide column names as well.