read.csv with Dates in 3 columns
read.csv, converting 3-column dates
into vectors of class Date.
readDates3to1(file, YMD=c('Year', 'Month', 'Day'),
...)Some files (e.g., from the
Correlates
of War project) have dates specified in
three separate columns with names like
startMonth1, startDay1,
startYear1, endMonth1, ...,
endYear2. This function looks for
such triples and replaces each found with
a single column with a name like,
start1, end1, ..., end2.
ALGORITHM
1. dat <- read.csv(file, ...)
2. Dates3to1(dat, YMD)
a data.frame with 3-column
dates replace by single-column vectors of class
Date.
Spencer Graves
##
## 1. Write a file to be read
##
cow0 <- data.frame(rec=1:3, startMonth=4:6,
startDay=7:9, startYear=1971:1973,
endMonth1=10:12, endDay1=13:15,
endYear1=1974:1976, txt=letters[1:3])
cowFile <- tempfile('cow0')
write.csv(cow0, cowFile, row.names=FALSE)
##
## 2. Read it
##
cow0. <- readDates3to1(cowFile)
# check
cow0x <- data.frame(rec=1:3, txt=letters[1:3],
start=as.Date(c('1971-04-07', '1972-05-08', '1973-06-09')),
end1=as.Date(c('1974-10-13', '1975-11-14', '1976-12-15')) )
all.equal(cow0., cow0x)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.