Split Date to Day, Month and Year for ffdf Data in R

Question

I'm using R's ff package with ffdf objects named MyData, (dim=c(10819740,16)). I'm trying to split the variable Date into Day, Month and Year and add these 3 variables into ffdf existing data MyData.

For instance: My Date column named SalesReportDate with VirtualVmode and PhysicalVmode = double after I've changed SalesReportDate to as.date(,format="%m/%d/%Y").

Example of SalesReportDate are as follow:

> B
  SalesReportDate
1       2013-02-01
2       2013-05-02
3       2013-05-04
4       2013-10-06
5       2013-15-10
6       2013-11-01
7       2013-11-03
8       2013-30-02
9       2013-12-12
10      2014-01-01

I've refer to Split date into different columns for year, month and day and try to apply it but keep getting error warning.

So, is there any way for me to do this? Thanks in advance.

Answer 1

Credit to @jwijffels for this great solution:

require(ffbase)

MyData$SalesReportDateYear <- with(MyData["SalesReportDate"], format(SalesReportDate, "%Y"), by = 250000) 

MyData$SalesReportDateMonth <- with(MyData["SalesReportDate"], format(SalesReportDate, "%m"), by = 250000) 

MyData$SalesReportDateDay <- with(MyData["SalesReportDate"], format(SalesReportDate, "%d"), by = 250000)