[R] subset problem

jim holtman jholtman at gmail.com
Thu Mar 15 04:35:33 CET 2012


Supply an 'str' of your dataframe so we can see what its structure is.
 Do you have leading/trailing blanks in your ROUTE values.   Print
them out and see what their number of characters (nchar) are.  Are
they factors?  You have not supplied enough information like a small
subset.  I bet when you create a small subset that includes the ROUTE
you are using in your subset, you will see the problem especially if
you use 'dput' to create it.

On Wed, Mar 14, 2012 at 9:02 PM, Farley, Robert <FarleyR at metro.net> wrote:
> I'm having a simple problem with subset.  I'm choosing what I think is a valid selection, but I either get everything or an empty dataframe.  What am I doing wrong?
>
>>
>> describe(OBDataSumm)
> Description of OBDataSumm
>
> Numeric
>                      mean    median       var        sd   valid.n
> SAMPN            2.155e+05 1.733e+05 1.151e+10 1.073e+05 3.378e+04
> PATTERN              62.78        35      5285      72.7 3.378e+04
> ASSN                  8139      8116 3.378e+07      5812 3.378e+04
> ~~Clip~~~
> ROUTE
> Value                                 Count Percent
> MT-802                             2297      6.8
> MT-801                             1552     4.59
> MT-804                             1159     3.43
> MT-803                              776      2.3
> MT-805                              744      2.2
> MT-.51                              504     1.49
> MT-.53                              413     1.22
> MT-.35                              377     1.12
> MT-.18                              363     1.07
> MT-252                              361     1.07
> mode = MT-802    Valid n = 33782   165 categories - only first 1
> ~~Clip~~~
>> dim(OBDataSumm)
> [1] 33782   130
>> SubRed <- subset(OBDataSumm, ROUTE == "MT-802")
>> dim(SubRed)
> [1]   0 130
>>
>
>
>
>
> Robert Farley
> LACMTA
> 1 Gateway Plaza
> Los Angeles, CA 90012-2952
> (213)922-2532
> FarleyR at Metro.net
>
>
>        [[alternative HTML version deleted]]
>
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-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.



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