Displaying 7 results from an estimated 7 matches for "nsnps".
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2007 May 25
1
Speeding up resampling of rows from a large matrix
...types,
each pair of haplotypes forms a genotype, and each column corresponds
to a SNP. I'm using resampling to compute the null distribution of
the maximum over correlated SNPs of a simple statistic.
The code:
#-------------------------------------------------------------------------------
nSNPs <- 1000
H <- matrix(sample(0:1, 120*nSNPs , replace=T), nrow=120)
G <- matrix(0, nrow=3, ncol=nSNPs)
# Keep in mind that the real H is 120 x 65000
nResamples <- 3000
pair <- replicate(nResamples, sample(1:120, 2))
gen <- function(x){g <- sum(x); c(g==0, g==1, g==2)}
for (i i...
2012 Aug 24
0
A question about GRAMMAR calculations in the FAM_MDR algorithm
...woutput.txt")
# loading data and bringing in GenABEL format
rawfile="simulation.raw"
convert.snp.ped(pedfile, mapfile, rawfile)
simulation.GenABEL = load.gwaa.data(phenofile = phenofil, genofile =
rawfile, force=F,makemap=F,sort=F)
pedigree=read.table(pedfile)
pedsize=nrow(pedigree)
nsnps=(ncol(pedigree)-6)/2
# minor allele count and handling missing genotype data
allelic = function(k){
geno=pedigree[,(5+2*k):(6+2*k)]
allelic=rowSums(geno==2)-(geno[,1]==0 & geno[,2]==0) # -1 for
missing, 0,1,2 gives count of variant allele
}
# preparing MB-MDR
SNPS = matrix(0,nrow=p...
2006 May 02
4
Repeating tdt function on thousands of variables
I am using dgc.genetics to perform TDT analysis on SNP data from a cohort of
trios.
I now have a file with about 6008 variables. The first few variables related
to the pedigree data such as the pedigree ID the person ID etc. Thereafter
each variable is a specific locus or marker. The variables are named by a
pattern such as "Genotype.nnnnn" with nnnnn corresponding to a number which
2010 May 20
1
ERROR: cannot allocate vector of size?
...4 on a Linux x86_64 Redhat cluster system. When I
log in, based on the specs I provide [qsub -I -X -l arch=x86_64] I am
randomly assigned to a x86_64 node.
I am using package GenABEL. My data (~ 650,000 SNPs, 3,000 people) loads in
okay and I am able to look at the data using basic commands [nids, nsnps,
names(phdata)]
The problem occurs when I try to run the extended analysis: xs <-
mlreg(GASurv(age,dm2)~sex,dta)
******************
1) I have looked through the memory limits on R
mem.limits()
nsize vsize
NA NA
2) Code:
gc()
used (Mb) gc trigger (Mb) max used (Mb)
Ncell...
2011 Feb 03
1
bug in codetools/R CMD check?
...<- rbind(value, new)
assign("srcinfo", value, entry)
Apply this "fix" would result in snpMatrix's "R CMD check" churning out:
---------------------
.ld.withmany: local variable ?names.components? assigned but may not be used
.ld.withmany: local variable ?nsnps.for.each? assigned but may not be used
misinherits: local variable ?nc.snps? assigned but may not be used
misinherits: local variable ?nr.snps? assigned but may not be used
qq.chisq: local variable ?lab? assigned but may not be used
read.HapMap.data: local variable ?base? assigned but may not be us...
2006 Jun 05
3
Fastest way to do HWE.exact test on 100K SNP data?
...dure multiple times (~1000) permuting the cases and
controls (affection status). It seems straightforward to implement it like this:
#############################################
for (iter in 1:1000) {
set.seed(iter)
# get the permuted affection status
permut <- sample(affSt)
for (j in 1:nSNPs) {
test <- tapply(all.geno[[j]], permut, HWE.exact)
pvalControls[j] <- test$"1"$p.value
pvalCases[j] <- test$"2"$p.value
}
}
##############################################
The problem is that it takes ~1 min/iteration (on AMD Opteron 252 processor
runnin...
2010 Oct 31
1
R-help Digest, Vol 92, Issue 31
...with possible haplotype
configurations for each subject weighted by their posterior
probabilities given genotype data.
Are your markers SNPs? If so you can use a utility function from the
hapassoc package to get started. For example, if your data is in a
dataframe dat, with nsnp SNPs in the last nsnps columns, you could
create an augmented data frame (augmented by pseudo-individuals for
each subject with ambiguous phase) with
library(hapassoc)
ph<-pre.hapassoc(dat,nsnps)
augdat<-cbind(ph$nonHaploDM,ph$haploDM)
wts<-ph$wt
and then use coxph with augdat as the data frme and wts as the...