R help - Apr 2009 - numbers not behaving as expected

If someone can explain this odd behavior I'd appreciate it.

I have a data.frame Cell.ave (attached and created via dput(Cell.ave,
"Cell.ave")
which contains three columns of parameters year, month and AveRain.

I need to subset the data.frame by months such that

DrySeaonMonths are 1,2,3,4, 11, and 12 or Jan - April, November and
December

and

WetSeasonMonths are 5:10 or May-October.

I'm using the following code:
> DrySeasonMonths <- Cell.ave[Cell.ave$month < "5" &
Cell.ave$month !"10",]
> table(DrySeasonMonth$month)
    1    2   3    4     11   12
 36   36  36  36  36   36

#  this is expected since the data is for 36 years

WetSeasonMonths <- Cell.ave[Cell.ave$month  >= "5" &
Cell.ave$month <"11",]
 WetSeasonMonths
[1] year    month   AveRain
<0 rows> (or 0-length row.names)
>
There is an obvious problem with how the values for month are being stored.
I've tried converting them to factors, which complines that the subsetting
routine is not appropriate for factors. And I've tried as.numeric which
also does not return an working dataframe.

all suggestions to solve this are appreciated.

Thanks Steve

(See attached file: Cell.ave)

sessionInfo()
R version 2.8.1 (2008-12-22)
x86_64-redhat-linux-gnu

locale:
LC_CTYPE=en_US.UTF-8;LC_NUMERIC=C;LC_TIME=en_US.UTF-8;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=en_US.UTF-8;LC_PAPER=en_US.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-8;LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base



Steve Friedman Ph. D.
Spatial Statistical Analyst
Everglades and Dry Tortugas National Park
950 N Krome Ave (3rd Floor)
Homestead, Florida 33034

Steve_Friedman at nps.gov
Office (305) 224 - 4282
Fax     (305) 224 - 4147

On Thu, Apr 9, 2009 at 1:39 PM,  <Steve_Friedman at nps.gov>
wrote:
> I have a data.frame Cell.ave (attached and created via dput(Cell.ave,
> "Cell.ave")
I'm afraid your attachment didn't make it into the r-help mail.
Mailing list policy forbids binary attachments other than PS and PDF,
but should be forwarding plaintext attachments, I think.  Perhaps it
requires that the extension be ".txt" or something...?

Anyway... the problem seems diagnosable just from your code:
> WetSeasonMonths <- Cell.ave[Cell.ave$month ?>= "5" &
Cell.ave$month <> "11",]
There is no *string* which is >= "5" and <= "11".  Why
aren't you
comparing numerically?

             -s

Steve_Friedman at nps.gov wrote:
> If someone can explain this odd behavior I'd appreciate it.
> 
> I have a data.frame Cell.ave (attached and created via dput(Cell.ave,
> "Cell.ave")
> which contains three columns of parameters year, month and AveRain.
> 
> I need to subset the data.frame by months such that
> 
> DrySeaonMonths are 1,2,3,4, 11, and 12 or Jan - April, November and
> December
> 
> and
> 
> WetSeasonMonths are 5:10 or May-October.
> 
> I'm using the following code:
> 
>> DrySeasonMonths <- Cell.ave[Cell.ave$month < "5" &
Cell.ave$month !> "10",]
>> table(DrySeasonMonth$month)
>     1    2   3    4     11   12
>  36   36  36  36  36   36
> 
> #  this is expected since the data is for 36 years
> 
> WetSeasonMonths <- Cell.ave[Cell.ave$month  >= "5" &
Cell.ave$month <> "11",]
>  WetSeasonMonths
> [1] year    month   AveRain
> <0 rows> (or 0-length row.names)
> 
> There is an obvious problem with how the values for month are being stored.
> I've tried converting them to factors, which complines that the
subsetting
> routine is not appropriate for factors. And I've tried as.numeric which
> also does not return an working dataframe.
> 
> all suggestions to solve this are appreciated.
> 
> Thanks Steve
> 
> (See attached file: Cell.ave)

In fact no longer attached (removed by mailing list), but it is 
sufficient if you just tell us the result of
str(Cell.ave$month)
instead.

Uwe Ligges



> sessionInfo()
> R version 2.8.1 (2008-12-22)
> x86_64-redhat-linux-gnu
> 
> locale:
>
LC_CTYPE=en_US.UTF-8;LC_NUMERIC=C;LC_TIME=en_US.UTF-8;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=en_US.UTF-8;LC_PAPER=en_US.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-8;LC_IDENTIFICATION=C
> 
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
> 
> 
> 
> Steve Friedman Ph. D.
> Spatial Statistical Analyst
> Everglades and Dry Tortugas National Park
> 950 N Krome Ave (3rd Floor)
> Homestead, Florida 33034
> 
> Steve_Friedman at nps.gov
> Office (305) 224 - 4282
> Fax     (305) 224 - 4147
> 
> 
> ------------------------------------------------------------------------
> 
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