R help - Jan 2008 - filtering data frame based on two columns

Hi,

 I have a data frame df with column names a,b and c.

 Now I want to get a subset of df that satified the condition a == 1 and b 
== 2, how do I specify this.

 For one condition like a == 1 I can use subdf = df[,df$a==1] to get the 
right answer, but
subdf = df[,df$a==1 && df$b ==2] does not return the right answer.

Some quick tips please.

"sun" <flyhyena at yahoo.com.cn> wrote in message 
news:fm7mtb$tqk$1 at ger.gmane.org...
> Hi,
>
> I have a data frame df with column names a,b and c.
sorry for some typos.

should be subdf = df[df$a==1,]
and
subdf = df[df$a==1 && df$b ==2,]

Use a single "&"

subdf = df[(df$a==1) & (df$b ==2),]

On Jan 11, 2008 7:26 AM, sun <flyhyena at yahoo.com.cn>
wrote:
>
> "sun" <flyhyena at yahoo.com.cn> wrote in message
> news:fm7mtb$tqk$1 at ger.gmane.org...
> > Hi,
> >
> > I have a data frame df with column names a,b and c.
> sorry for some typos.
>
> should be subdf = df[df$a==1,]
> and
> subdf = df[df$a==1 && df$b ==2,]
>
>
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>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?

Thanks, Jim. Works fine.

"jim holtman" <jholtman at gmail.com> wrote in message 
news:644e1f320801110432l29c7d2ccia2d59099b800827b at
mail.gmail.com...
> Use a single "&"