adding NA to "subset"

Try this:


is.na <http://is.na>(spdco2[,2]) <- which(spdco2[,2] < 4.7)
spdco2

On Thu, Sep 4, 2008 at 4:21 PM, Sherri Heck <sheck at ucar.edu 
<mailto:sheck at ucar.edu>> wrote:

    Hi All-

    I have a data set (spdco2)

    > spdco2

        [,1] [,2]     [,3]
    [1,]    1  5.4 382.4212
    [2,]    2  5.1 383.0315
    [3,]    3  4.8 383.9520
    [4,]    4  4.7 384.4376
    [5,]    5  4.7 384.5929
    [6,]    6  4.4 384.8864
    [7,]    7  4.1 385.2156
    [8,]    8  3.8 385.2919
    [9,]    9  3.7 385.5925
    [10,]   10  3.9 385.6801


    I am subsetting it to output when [,2] is >= 4.7 .
    x<-subset(spdco2,spdco2[,2]>=4.7)

    This works, but I would like to add 'NA' to the data that it does
    exclude based on my subset criteria.  I have searched through the
    archives and two R books, but I cannot figure out how to add the NA.
    Any suggestions would be appreciated-

    thanks!

    sherri





    x<-subset(spdco2,spdco2[,2]>=4.7)