as.Date: fixed

On Apr 18, 2016, at 10:44 AM, Ogbos Okike <giftedlife2014 at gmail.com>

wrote:

Dear ALL,
Thank you so much for your contributions.
I have made some progress. Below is a simple script I gleaned from
your kind responses:
Sys.setenv(TZ="Etc/GMT")
dates <- c("02/27/92", "02/27/92", "01/14/92", "02/28/92", "02/01/92")
    times <- c("23:0:0", "22:0:0", "01:00:00", "18:0:0", "16:0:0")
    x <- paste(dates, times)
    aa<-strptime(x, "%m/%d/%y %H:%M:%S")
bb<-1:5
plot(aa, bb)

I tried plotting my result and I got what I am looking for. I think I
am almost there.

I am, however, stuck here. My data is a large file and the form
differs a little from the example I used. The quotation marks in both
date and time is my headache now. Such inverted commas are not in my
data. I can with awk transform my data to get exactly something like
dd/mm/yy. But I wont know how to make the data appear in quotation
mark in R.

There are not any quotation marks in an R object that is displayed as
"02/27/92". The quotation marks are just added by the print function to
make it clear to the user that it is a character value.

If you read such values in with read.table they would automatically be
interpreted as character values and then converted to factor class (which
you do not want). Read up on the use in the read.* functions for colClasses
and stringsAsFactors to safely input character values.
--
David.

I will once more be glad for any more help.
Ogbos

PS: I am still afraid of this forum. Please direct me to the right
forum if this is not ok. Thanks again.


On 4/18/16, peter dalgaard <pdalgd at gmail.com> wrote:

The most important thing is that Date objects by definition do not

include

time of day. You want to look at ISOdatetime() and as.POSIXct()

instead. And

beware daylight savings time issues.

-pd

On 18 Apr 2016, at 15:09 , Ogbos Okike <giftedlife2014 at gmail.com>

wrote:

Dear All,

I have a data set containing year, month, day and counts as shown

below:

data <- read.table("data.txt", col.names = c("year", "month", "day",
"counts"))
Using the formula below, I converted the data to as date and plotted.

new.century <- data$year < 70

data$year <- ifelse(new.century, data$year + 2000, data$year + 1900)

data$date <- as.Date(ISOdate(data$year, data$month, data$day))

The form of the data is:
16 1 19 9078
16 1 20 9060
16 1 21 9090
16 1 22 9080
16 1 23 9121
16 1 24 9199
16 1 25 9289
16 1 26 9285
16 1 27 9245
16 1 28 9223
16 1 29 9298
16 1 30 9327
16 1 31 9365

Now, I wish to include time (hour) in my data. The new data is of the
form:
05 01 06 14    3849
05 01 06 15    3845
05 01 06 16    3836
05 01 06 17    3847
05 01 06 18    3850
05 01 06 19    3872
05 01 06 20    3849
05 01 06 21    3860
05 01 06 22    3868
05 01 06 23    3853
05 01 07 00    3839
05 01 07 01    3842
05 01 07 02    3843
05 01 07 03    3865
05 01 07 04    3879
05 01 07 05    3876
05 01 07 06    3867
05 01 07 07    3887

I now read the data as:
data <- read.table("data.txt", col.names = c("year", "month", "day",
"counts", "hour")) and also included hour in data$date <-
as.Date(ISOdate(data$year, data$month, data$day))
i.e data$date <- as.Date(ISOdate(data$year, data$month, data$day,
data$hour)).

However, these did not work.

Can you please assist be on how to get this date and time in the right
format. The right format I got without hour looks like : 2005-12-29"
"2005-12-29" "2005-12-29" "2005-12-29" "2005-12-29"
[8696] "2005-12-29" "2005-12-29" "2005-12-29" "2005-12-29" "2005-12-29"
[8701] "2005-12-29" "2005-12-29" "2005-12-29" "2005-12-29" "2005-12-29"
[8706] "2005-12-29" "2005-12-29" "2005-12-29" "2005-12-29" "2005-12-29"

I used this in my plot. Please I want this format to include hour.

Many thanks for your help. I am just a newbe. I am not sure if this
forum is the right one. After registration, I tried to post to Nabble
forum where I registered but could not succeed.

If there is a mistake, please help/direct me to the right forum.

Best regards
Ogbos

--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com