Hi,
I 've a matrix n*1 (thus a column) and I would like to
count the number of negative element inside.
Can you help me?
Thanks!
eg:
res[,1]= 1
-3
-1
How obtain the number 2 (number of negative-element)?
How about this? length(res[res < 0, 1]) HTH, Andy> -----Original Message----- > From: r-help-bounces at stat.math.ethz.ch > [mailto:r-help-bounces at stat.math.ethz.ch]On Behalf Of Frederic renaud > Sent: Wednesday, January 05, 2005 11:08 AM > To: r-help at stat.math.ethz.ch > Subject: [R] count element in column > > > Hi, > I 've a matrix n*1 (thus a column) and I would like to > count the number of negative element inside. > Can you help me? > Thanks! > > eg: > res[,1]= 1 > -3 > -1 > > How obtain the number 2 (number of negative-element)? > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html >
On 05-Jan-05 Frederic renaud wrote:> Hi, > I 've a matrix n*1 (thus a column) and I would like to > count the number of negative element inside. > Can you help me? > Thanks! > > eg: > res[,1]= 1 > -3 > -1 > > How obtain the number 2 (number of negative-element)?If there is only one column, then either sum(x<0) or sum(x[,1]<0) If there is more than one column, then sum(x[,1]<0) sum(x[,2]<0) ... does it for each column, one at a time, and colSums(x<0) does it for all the columns at once (but separately), while sum(x<0) does it for the whole matrix (without regard for columns). Best wishes, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <Ted.Harding at nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 094 0861 [NB: New number!] Date: 05-Jan-05 Time: 17:43:03 ------------------------------ XFMail ------------------------------
How about
sum(res<0)?
--
robert.kruus at utoronto.ca
The computer should be doing the hard work. That's what it's paid to
do, after all.
-- Larry Wall in <199709012312.QAA08121 at wall.org>
--------
It is rumored that on Wed, 5 Jan 2005 08:07:34 -0800 (PST)
Frederic renaud <fren2 at yahoo.com> wrote:
> Hi,
> I 've a matrix n*1 (thus a column) and I would like to
> count the number of negative element inside.
> Can you help me?
> Thanks!
>
> eg:
> res[,1]= 1
> -3
> -1
>
> How obtain the number 2 (number of negative-element)?
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
>
--------
Something like colSums(res < 0), which works for any number of columns. Andy> From: Frederic renaud > > Hi, > I 've a matrix n*1 (thus a column) and I would like to > count the number of negative element inside. > Can you help me? > Thanks! > > eg: > res[,1]= 1 > -3 > -1 > > How obtain the number 2 (number of negative-element)? > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > >
Have you considered
> sum(res[,1]<0)
[1] 2
hope this helps. spencer graves
Frederic renaud wrote:
>Hi,
>I 've a matrix n*1 (thus a column) and I would like to
>count the number of negative element inside.
>Can you help me?
>Thanks!
>
>eg:
> res[,1]= 1
> -3
> -1
>
>How obtain the number 2 (number of negative-element)?
>
>______________________________________________
>R-help at stat.math.ethz.ch mailing list
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
>
>
How about
sum(res<0)?
--
robert.kruus at utoronto.ca
The computer should be doing the hard work. That's what it's paid to
do, after all.
-- Larry Wall in <199709012312.QAA08121 at wall.org>
--------
It is rumored that on Wed, 5 Jan 2005 08:07:34 -0800 (PST)
Frederic renaud <fren2 at yahoo.com> wrote:
> Hi,
> I 've a matrix n*1 (thus a column) and I would like to
> count the number of negative element inside.
> Can you help me?
> Thanks!
>
> eg:
> res[,1]= 1
> -3
> -1
>
> How obtain the number 2 (number of negative-element)?
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
>
--------
--
robert.kruus at utoronto.ca
A beginning is the time for taking the most delicate care that balances
are correct.
-- Princess Irulan, "Manual of Maud'Dib"
x<-c(-3. -4.7, -.005, 1, 9)> length(x[x<0])[1] 3 Anne ----- Original Message ----- From: "Frederic renaud" <fren2 at yahoo.com> To: <r-help at stat.math.ethz.ch> Sent: Wednesday, January 05, 2005 5:07 PM Subject: [R] count element in column> Hi, > I 've a matrix n*1 (thus a column) and I would like to > count the number of negative element inside. > Can you help me? > Thanks! > > eg: > res[,1]= 1 > -3 > -1 > > How obtain the number 2 (number of negative-element)? > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide!http://www.R-project.org/posting-guide.html>