On 03/20/2014 09:57 AM, Jason Rupert wrote:
Not sure I follow.
I would like the date formatting information preserved as is implemented
when using as.character:
MaxUpdated_row<-NULL
MaxUpdated_val<- "2013-06-28"
c(MaxUpdated_row, as.character(MaxUpdated_val))
[1] "2013-06-28"
However, when I try to used as.Date(...) I loose the date formatting
information:
c(MaxUpdated_row, as.Date(MaxUpdated_val, "%Y-%m-%d"))
[1] 15884
I thought as.Date was an instruction describing how the data element
should be represented?
Maybe as.character is the only way to preserve the "date" formatting
information in character string format in a vector and then just convert
it back later on...
As I wrote before, all of the data types in a vector object in R must be
the same. So when you catenate (c) two things that are different data
types, R coerces them to the same type. Because you are just displaying
the values in the vector you have created, it doesn't change the data
type of MaxUpdated_val:
MaxUpdated_val<-as.Date("2013-06-28","%Y-%m-%d")
# prints as a formatted date
MaxUpdated_val
[1] "2013-06-28"
# make a vector with a numeric and MaxUpdated_val
c(0,MaxUpdated_val)
# R coerces the value to numeric and prints both
[1] 0 15884
# now assign it to something
mynewmax<-c(0,MaxUpdated_val)
# in mynewmax the value is numeric
mynewmax
[1] 0 15884
# but MaxUpdated_val is still a date type on its own
MaxUpdated_val
[1] "2013-06-28"
Jim
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