I'm sure this is just the result of a basic misunderstanding of the
syntax of R, but I am stumped.
A <-
read.table(file="sumByThirtyMinute.csv",sep=",",col.names=c("date","pandl"))
A now consists of thousands of rows, but A$date is a string...
...
3183 2006-02-28 12:00:00 548.470
3184 2006-02-28 12:30:00 515.240
3185 2006-02-28 13:00:00 140.120
3186 2006-02-28 13:30:00 450.940
3187 2006-02-28 14:00:00 318.570
...
So, I try to convert A$date to a POSIXlt ...
A[,1]<-strptime(A$date,"%Y-%m-%d %H:%M:%s")
A$date<-strptime(A$date,"%Y-%m-%d %H:%M:%s")
which gives me a warning that the length of the array I am trying to
replace A$date with is 9 ... but if I print strptime(A$date,"%Y-%m-%d
%H:%M:%s"), it clearly has thousands of rows. Yet, if I ask for
length(strptime(A$date,"%Y-%m-%d %H:%M:%s")), I get 9.
What am I doing wrong? Do I need to convert the return value of
strptime(A$date,"%Y-%m-%d %H:%M:%s") to some array/vector/matrix
datatype before attempting to assign it?
Thanks,
Andrew