thr3ads.net - R help - [R] subset based on column names and then subset based on the inverse (grep?, or...) [Aug 2010]

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stephen sefick

2010-Aug-03 11:41 UTC

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

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

2010-Aug-03 11:44 UTC

head link

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

#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

David Winsemius

2010-Aug-03 11:53 UTC

head link

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

On Aug 3, 2010, at 7:41 AM, stephen sefick 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"
That would not parse properly because the expression on the rhs of  
"|", namely  "y", is not logical, but rather
character.>Try instead:

ftbr_UTM_downstream[ , grep("^x$|^y$", colnames(ftbr_UTM_downstream))]
ftbr_UTM_downstream[ , -grep("^x$|^y$",
colnames(ftbr_UTM_downstream))]

  or use the select argument to subset

subset(ftbr_UTM_downstream, select = colnames(ftbr_UTM_downstream) %in 
% c("x", "y") )
?"%in%"
subset(ftbr_UTM_downstream, select = colnames(ftbr_UTM_downstream)[
                                   !colnames(ftbr_UTM_downstream) %in%  
c("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
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT

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