[R] trouble parsing a date using strptime()

[jim holtman]

paste on a 'day' since it is trying to convert to something that is ambigous:

> strptime("2011010","%Y%W%w")
[1] "2011-01-02"
> strptime("2011520","%Y%W%w")
[1] "2011-12-25"
> strptime("2011120","%Y%W%w")
[1] "2011-03-20"
> strptime("2011200","%Y%W%w")
[1] "2011-05-15"



On Wed, Jul 6, 2011 at 3:17 PM, David Pitkin <dpitkin at pobox.com> wrote:
> Hi,
>
> I am having a trouble parsing dates using strptime() that I get in the
> format of year and week number. The data looks like this "201127" which
> means year 2011 and week 27. I would like to graph this using ggplot but
> then I get a gap between 201054 and 201101 so I thought I would just easily
> convert it.
>
> I tried to use strptime and as.Date and the format string of %Y%W but it
> seems to only parse the year out of the string and then return today's month
> and date. Can anyone point me where I am going wrong or another avenue to
> try?
>
> David
>
>> strptime("201101","%Y%W")[1] "2011-07-06"
>
>> strptime("201001","%Y%W")[1] "2010-07-06"
>
>> strptime("201114","%Y%W")[1] "2011-07-06"
>
>> strptime("201130","%Y%W")[1] "2011-07-06"
>
>
>
>> sessionInfo()
> R version 2.12.2 (2011-02-25)
> Platform: x86_64-pc-mingw32/x64 (64-bit)
>
> locale:
> [1] LC_COLLATE=English_United States.1252
> [2] LC_CTYPE=English_United States.1252
> [3] LC_MONETARY=English_United States.1252
> [4] LC_NUMERIC=C
> [5] LC_TIME=English_United States.1252
>
> attached base packages:
> [1] grid      stats     graphics  grDevices utils     datasets  methods
> [8] base
>
> other attached packages:
> [1] RSiteSearch_1.0-7 sos_1.3-0         brew_1.0-6        ggplot2_0.8.9
> [5] proto_0.3-9.1     reshape_0.8.4     plyr_1.4          RODBC_1.3-2
>
> loaded via a namespace (and not attached):
> [1] digest_0.4.2 tools_2.12.2
>
>        [[alternative HTML version deleted]]
>
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>



-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?