[R] why the a[-indx] does not work?

[William Dunlap]

  myvec != 0
does the same as
  ifelse(myvec == 0, FALSE, TRUE)
but more quickly

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com 

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Sarah Goslee
> Sent: Sunday, October 30, 2011 12:57 PM
> To: Alaios
> Cc: R-help at r-project.org
> Subject: Re: [R] why the a[-indx] does not work?
> 
> ifelse(myvec == 0, FALSE, TRUE) # set 0 to FALSE, other values to TRUE
> 
> 
> 
> On Sun, Oct 30, 2011 at 3:50 PM, Alaios <alaios at yahoo.com> wrote:
> > probably you mean
> >
> >
> >
> >
> > For '['-indexing only: 'i', 'j', '...' can be logical
> > vectors, indicating elements/slices to select.  Such vectors
> > are recycled if necessary to match the corresponding extent.
> > 'i', 'j', '...' can also be negative integers, indicating
> > elements/slices to leave out of the selection.
> >
> >
> >
> > How can i convert the positives to TRUE and zeros and FALSE?
> >
> >
> >
> > ________________________________
> > From: William Dunlap <wdunlap at tibco.com>
> >
> > Sent: Sunday, October 30, 2011 9:17 PM
> > Subject: RE: [R] why the a[-indx] does not work?
> >
> >   > a[overLoadTesT==0]
> >   [1]  2  4  5  6  7  8  9 10
> > Look into help('[') or help('Subscript') to see
> > how integer and logical (Boolean) subscripts differ.
> >
> > Bill Dunlap
> > Spotfire, TIBCO Software
> > wdunlap tibco.com
> >
> >> -----Original Message-----
> >> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Alaios
> >> Sent: Sunday, October 30, 2011 11:52 AM
> >> To: R-help at r-project.org
> >> Subject: [R] why the a[-indx] does not work?
> >>
> >> Dear all,
> >>
> >> Could you please explain me why
> >>
> >> > OverloadsTesT
> >> [1] 1 0 1 0 0 0 0 0 0 0
> >> > a<-matrix(data=seq(1,10),nrow=10)
> >> > a
> >> [,1]
> >> [1,]    1
> >> [2,]    2
> >> [3,]    3
> >> [4,]    4
> >> [5,]    5
> >> [6,]    6
> >> [7,]    7
> >> [8,]    8
> >> [9,]    9
> >> [10,]   10
> >> > a[-OverloadsTesT]
> >> [1]  2  3  4  5  6  7  8  9 10
> >>
> >>
> >>
> >> the last line does not remove the first and third element and only does the first element.?
> >>
> >> What I want to do is for zeros to return the elements and for any positive value to remove it.
> >> What I am doing wrong?
> >>
> 
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