R help - Apr 2009 - Subset function: selecting variables within a factor

Hi all

I know this must be an easy one so sorry for the trouble. I would like
to select a list of variables within a factor 
The following example is given in help for subset:

subset(airquality, Temp  > 80 select = c(Ozone, Temp))

So how do I select all temperatures of 90 and 80 ie Temp = c(80,90) 


I would appreciate your help.

Kind regards

andy

Andrew McFadden MVS BVSc
Incursion Investigator
Investigation & Diagnostic Centres - Wallaceville Biosecurity New 
Zealand Ministry of Agriculture and Forestry

Phone 04 894 5600 Fax 04 894 4973 Mobile 029 894 5611 Postal address: 
Investigation and Diagnostic Centre- Wallaceville Box 40742 Ward St 
Upper Hutt


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On Tue, 14 Apr 2009, Andrew McFadden wrote:
> Hi all
>
> I know this must be an easy one so sorry for the trouble. I would like
> to select a list of variables within a factor
> The following example is given in help for subset:
>
> subset(airquality, Temp  > 80 select = c(Ozone, Temp))
>
> So how do I select all temperatures of 90 and 80 ie Temp = c(80,90)

subset(airquality, Temp %in% c(80,90))

    -thomas

Thomas Lumley			Assoc. Professor, Biostatistics
tlumley at u.washington.edu	University of Washington, Seattle

Hey Thomas Thanks mate

I knew there had to be an easy answer. Thanks for coming to my rescue.

Regards

Andrew McFadden MVS BVSc | Incursion Investigator (animals), 
Investigation and Diagnostic Centre | Biosecurity New Zealand
Ministry of Agriculture and Forestry | 66 Ward St,  Wallaceville | PO
Box 40 742 | Upper Hutt | New Zealand 
Telephone: 64-4-894 5611 | Facsimile: 64-4-894 4973| Mobile:
027-733-1791 | Web: www.maf.govt.nz


-----Original Message-----
From: Thomas Lumley [mailto:tlumley at u.washington.edu] 
Sent: Tuesday, 14 April 2009 3:29 p.m.
To: Andrew McFadden
Cc: r-help at r-project.org
Subject: [Requires Classification] Re: [R] Subset function: selecting
variables within a factor

On Tue, 14 Apr 2009, Andrew McFadden wrote:
> Hi all
>
> I know this must be an easy one so sorry for the trouble. I would like
> to select a list of variables within a factor The following example is
> given in help for subset:
>
> subset(airquality, Temp  > 80 select = c(Ozone, Temp))
>
> So how do I select all temperatures of 90 and 80 ie Temp = c(80,90)

subset(airquality, Temp %in% c(80,90))

    -thomas

Thomas Lumley			Assoc. Professor, Biostatistics
tlumley at u.washington.edu	University of Washington, Seattle


########################################################################
This email message and any attachment(s) is intended solely for the
addressee(s) named above. The information it contains is confidential
and may be legally privileged.  Unauthorised use of the message, or the
information it contains, may be unlawful. If you have received this
message by mistake please call the sender immediately on 64 4 8940100
or notify us by return email and erase the original message and
attachments. Thank you.

The Ministry of Agriculture and Forestry accepts no responsibility for
changes made to this email or to any attachments after transmission from
the office.
########################################################################