[R] How to extract information from the following dataset?

[Jose-Marcio Martins da Cruz]

Xin Zhang wrote:
> Hi all,
>
> I have never worked with this kind of data before, so Please help me out
> with it.
> I have the following data set, in a csv file, looks like the following:
>
> Jan 27, 2010  16:01:24,000 125 - - -
> Jan 27, 2010  16:06:24,000 125 - - -
> Jan 27, 2010  16:11:24,000 176 - - -
> Jan 27, 2010  16:16:25,000 159 - - -
> Jan 27, 2010  16:21:25,000 142 - - -
> Jan 27, 2010  16:26:24,000 142 - - -
> Jan 27, 2010  16:31:24,000 125 - - -
> Jan 27, 2010  16:36:24,000 125 - - -
> Jan 27, 2010  16:41:24,000 125 - - -
> Jan 27, 2010  16:46:24,000 125 - - -
> Jan 27, 2010  16:51:24,000 125 - - -
> Jan 27, 2010  16:56:24,000 125 - - -
> Jan 27, 2010  17:01:24,000 157 - - -
> Jan 27, 2010  17:06:24,000 172 - - -
> Jan 27, 2010  17:11:25,000 142 - - -
> Jan 27, 2010  17:16:24,000 125 - - -
> Jan 27, 2010  17:21:24,000 125 - - -
> Jan 27, 2010  17:26:24,000 125 - - -
> Jan 27, 2010  17:31:24,000 125 - - -
> Jan 27, 2010  17:36:24,000 125 - - -
> Jan 27, 2010  17:41:24,000 125 - - -
> Jan 27, 2010  17:46:24,000 125 - - -
> Jan 27, 2010  17:51:24,000 125 - - -
> ......
>
> The first few columns are month, day, year, time with OS3 accuracy. And the
> last number is the measurement I need to extract.
> I wonder if there is a easy way to just take out the measurements only from
> a specific day and hour, i.e. if I want measurements from Jan 27 2010
> 16:--:--
> then I get 125,125,176,159,142,142,125,125,125,125,125,125.
> Many thanks!!

The easiest is in the shell, if you're using some flavour of unix :

grep "Jan 27, 2010  16" filein.txt | awk '{print $5}' > fileout.txt

and use fileout which will contain only the column of data you want.

>

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