[R] subset based on column names and then subset based on the inverse (grep?, or...)

stephen sefick ssefick at gmail.com
Tue Aug 3 13:44:01 CEST 2010


#this does it sorry for clogging everyones email boxes
 charmatch(c("x", "y"), colnames(ftbr_UTM_downstream))

On Tue, Aug 3, 2010 at 6:41 AM, stephen sefick <ssefick at gmail.com> wrote:
> I would like to be able to grab x and y columns out of a dataframe and
> then grab all of the columns that are not equal to x or y.  I am sure
> that I am missing something easy.
>
>
> ftbr_UTM_downstream <- (structure(list(site =
> c("Jennie_Creek_Main_Stem", "Wolf_Pit_Creek_Main_Stem",
> "Little_Rockfish_Main_Stem_North", "Big_Muddy_Creek_Main_Stem",
> "Flat_Creek_Main_Stem", "little_river_tributary", "Hector_Creek_Main_Stem",
> "Juniper_Creek_Main_Stem", "Field_Branch_Main_Stem", "Gum_Branch_Main_Stem"
> ), base = c("ftbr", "ftbr", "ftbr", "ftbr", "ftbr", "ftbr", "ftbr",
> "ftbr", "ftbr", "ftbr"), creek = c("jcms", "wpms", "lrf1", "bmcm",
> "fcms", "lrtb", "hcms", "jpms", "fbms", "gbms"), date = c("06/20/2010",
> "06/20/2010", "06/18/2010", "06/18/2010", "06/21/2010", "06/22/2010",
> "06/22/2010", "06/21/2010", "06/19/2010", "06/19/2010"), elevation_m = c(101,
> 81, 59, 75, 73, 55, 55, 88, 77, 87), x = c(652159, 651646, 674147,
> 635466, 665726, 675295, 673098, 658917, 655613, 651748), y = c(3887647,
> 3886986, 3893724, 3876272, 3893886, 3895529, 3895076, 3882474,
> 3881587, 3884249), station = c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1),
>    notes_ = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA)), .Names = c("site",
> "base", "creek", "date", "elevation_m", "x", "y", "station",
> "notes_"), row.names = c("1", "3", "5", "7", "9", "11", "13",
> "15", "17", "19"), class = "data.frame"))
>
> #this doesn't work, but I would like it to.  I also tried grep to no avail
>
> colnames(ftbr_UTM_downstream)=="x" | "y"
>
>
> --
> Stephen Sefick
> ____________________________________
> | Auburn University                                   |
> | Department of Biological Sciences           |
> | 331 Funchess Hall                                  |
> | Auburn, Alabama                                   |
> | 36849                                                    |
> |___________________________________|
> | sas0025 at auburn.edu                             |
> | http://www.auburn.edu/~sas0025             |
> |___________________________________|
>
> Let's not spend our time and resources thinking about things that are
> so little or so large that all they really do for us is puff us up and
> make us feel like gods.  We are mammals, and have not exhausted the
> annoying little problems of being mammals.
>
>                                 -K. Mullis
>



-- 
Stephen Sefick
____________________________________
| Auburn University                                   |
| Department of Biological Sciences           |
| 331 Funchess Hall                                  |
| Auburn, Alabama                                   |
| 36849                                                    |
|___________________________________|
| sas0025 at auburn.edu                             |
| http://www.auburn.edu/~sas0025             |
|___________________________________|

Let's not spend our time and resources thinking about things that are
so little or so large that all they really do for us is puff us up and
make us feel like gods.  We are mammals, and have not exhausted the
annoying little problems of being mammals.

                                -K. Mullis



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