Dates3to1: Convert 3-column dates in data to class Date
In Ecfun: Functions for Ecdat

Description Usage Arguments Details Value Author(s) See Also Examples

Return a data.frame with columns of class "Date" replaceing all 3-column dates.

1	Dates3to1(data, YMD=c('Year', 'Month', 'Day'))

`data`	a `data.frame` assumed to include dates coded in three column sets with names matching `YMD`.
`YMD`	a character vector of lenght 3 of patterns to use in `grep` to identify triples of columns coding `YMD` in `col.names(data)`.

The data sets from the Correlates of War project include dates coded in triples of columns with names like c("StartMonth1", "StartDay1", "StartYear1", "EndMonth1", ..., "EndYear2"). This function will accept a data.frame obtained via read.csv of such a file and replace each such triple with a singe column of class 'Date' combining the triple appropriately.

Return a data.frame containing the information in data reformatted as described above.

Spencer Graves

dateCols Date3to1

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])

cow0. <- Dates3to1(cow0)

# 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)