R help - Sep 2003 - multiple selection syntax

Hello

This is a very newbie question on R syntax, but I do not find the answer....

I want to make a selection on an interval say choose Xint in the 
interval of temperatures 390-399

I tried this syntax
Xint<- X[t>=390 && t< 400] 
typing >XintI get the answer numeric(0)

it did not select any object! 'though I verified that there indeed are 
occrencies of X in this interval


Any idea?

thanks

Anne

anne wrote:
> Hello
> 
> This is a very newbie question on R syntax, but I do not find the 
> answer....
> 
> I want to make a selection on an interval say choose Xint in the 
> interval of temperatures 390-399
> 
> I tried this syntax
> Xint<- X[t>=390 && t< 400] typing >XintI get the answer
numeric(0)
> 
> it did not select any object! 'though I verified that there indeed are 
> occrencies of X in this interval
> 
> 
> Any idea?
> 
> thanks
> 
> Anne
The idea is to read help("&&"). It tells you:

"& and && indicate logical AND and | and || indicate logical
OR. The
shorter form performs elementwise comparisons in much the same way as 
arithmetic operators. The longer form evaluates left to right examining 
only the first element of each vector. Evaluation proceeds only until 
the result is determined. The longer form is appropriate for programming 
control-flow and typically preferred in if clauses."

So I guess you want
  Xint <- X[(t >= 390) & (t < 400)]

Uwe Ligges

anne <anne.piotet at urbanet.ch> writes:
> Hello
> 
> This is a very newbie question on R syntax, but I do not find the
answer....
> 
> I want to make a selection on an interval say choose Xint in the
> interval of temperatures 390-399
> 
> 
> I tried this syntax
> Xint<- X[t>=390 && t< 400] typing >XintI get the answer
numeric(0)
Use &, not &&

I think you just want &, not &&.

  
try:
 x <- 1:10
 xint <- x[x>=4 & x < 7]
 xint


At 05:57 PM 9/8/2003 +0200, anne wrote:
>Hello
>
>This is a very newbie question on R syntax, but I do not find the answer....
>
>I want to make a selection on an interval say choose Xint in the 
>interval of temperatures 390-399
>
>I tried this syntax
>Xint<- X[t>=390 && t< 400] 
>typing >XintI get the answer numeric(0)
>
>it did not select any object! 'though I verified that there indeed are 
>occrencies of X in this interval
>
>
>Any idea?
>
>thanks
>
>Anne
>
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>R-help at stat.math.ethz.ch mailing list
>https://www.stat.math.ethz.ch/mailman/listinfo/r-help
>
With best wishes and kind regards I am

Sincerely,

Corey A. Moffet, Ph.D.
Support Scientist

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