Re: [R] vectorising ifelse()
Does either 'zippo' or 'zappo' contain the values 1 or 2 ?
If so, then you cannot vectorize this code because you are changing the
values in 'new' at every iteration and potentially sampling a value from
new[ ,1] or new[ ,2] .
If not, then it might be possible to vectorize. Something along the
following untested lines
pos - which( srow 0 )
neg - which( srow = 0 )
new[pos ,1] - new[ cbind(srow[pos] , zippo[pos]) ]
new[neg, 1] - sample( 1:100, length(neg), prob=Y1, replace=TRUE )
and then repeat for filling in new[ ,2].
Am I correct in guessing that your srow and zippo are of the equal
length here and thus new is a square matrix.
Regards, Adai
On Fri, 2005-07-22 at 00:44 +0100, Federico Calboli wrote:
Hi All,
is there any chance of vectorising the two ifelse() statements in the
following code:
for(i in gp){
new[i,1] = ifelse(srow[i]0, new[srow[i],zippo[i]], sample(1:100, 1,
prob =Y1, rep = T))
new[i,2] = ifelse(drow[i]0, new[drow[i]0,zappo[i]], sample(1:100,
1, prob =Y1, rep = T))
}
Where I am forced to check if the value of drow and srow are 0 for each
line... in practical terms, I am attributing haplotypes to a pedigree,
so I have to give the haplotypes to the parents before I give them to
the offspring. The vectors *zippo* and *zappo* are the chances of
getting one or the other hap from the sire and dam respectively. *gp* is
the vectors of non-ancestral animals. *new* is a two col matrix where
the haps are stored.
Cheers,
Federico
__
R-help@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
Re: [R] vectorising ifelse()
On 22 Jul 2005, at 11:20, Adaikalavan Ramasamy wrote: Does either 'zippo' or 'zappo' contain the values 1 or 2 ? If so, then you cannot vectorize this code because you are changing the values in 'new' at every iteration and potentially sampling a value from new[ ,1] or new[ ,2] . That's exactly my situation, and is exactly what I want to do. After taking out the typo (and bug) drow[i]0 the code seems to work fast enough... I'll tinker a bit with it, but it could be good enough as it is. Cheers, Federico Calboli -- Federico C. F. Calboli Department of Epidemiology and Public Health Imperial College, St. Mary's Campus Norfolk Place, London W2 1PG Tel +44 (0)20 75941602 Fax +44 (0)20 75943193 f.calboli [.a.t] imperial.ac.uk f.calboli [.a.t] gmail.com __ R-help@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
[R] vectorising ifelse()
Hi All,
is there any chance of vectorising the two ifelse() statements in the
following code:
for(i in gp){
new[i,1] = ifelse(srow[i]0, new[srow[i],zippo[i]], sample(1:100, 1,
prob =Y1, rep = T))
new[i,2] = ifelse(drow[i]0, new[drow[i]0,zappo[i]], sample(1:100,
1, prob =Y1, rep = T))
}
Where I am forced to check if the value of drow and srow are 0 for each
line... in practical terms, I am attributing haplotypes to a pedigree,
so I have to give the haplotypes to the parents before I give them to
the offspring. The vectors *zippo* and *zappo* are the chances of
getting one or the other hap from the sire and dam respectively. *gp* is
the vectors of non-ancestral animals. *new* is a two col matrix where
the haps are stored.
Cheers,
Federico
--
Federico C. F. Calboli
Department of Epidemiology and Public Health
Imperial College, St Mary's Campus
Norfolk Place, London W2 1PG
Tel +44 (0)20 7594 1602 Fax (+44) 020 7594 3193
f.calboli [.a.t] imperial.ac.uk
f.calboli [.a.t] gmail.com
__
R-help@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
