Mercurial > repos > xuebing > sharplabtool
view tools/rgenetics/rgLDIndep.py @ 0:9071e359b9a3
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author | xuebing |
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date | Fri, 09 Mar 2012 19:37:19 -0500 |
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""" # oct 2009 - must make a map file in case later usage requires it... # galaxy tool xml files can define a galaxy supplied output filename # that must be passed to the tool and used to return output # here, the plink log file is copied to that file and removed # took a while to figure this out! # use exec_before_job to give files sensible names # # ross april 14 2007 # plink cleanup script # ross lazarus March 2007 for camp illumina whole genome data # note problems with multiple commands being ignored - eg --freq --missing --mendel # only the first seems to get done... # ##Summary statistics versus inclusion criteria ## ##Feature As summary statistic As inclusion criteria ##Missingness per individual --missing --mind N ##Missingness per marker --missing --geno N ##Allele frequency --freq --maf N ##Hardy-Weinberg equilibrium --hardy --hwe N ##Mendel error rates --mendel --me N M # # this is rgLDIndep.py - main task is to decrease LD by filtering high LD pairs # remove that function from rgClean.py as it may not be needed. """ import sys,shutil,os,subprocess, glob, string, tempfile, time from rgutils import plinke, timenow, galhtmlprefix prog = os.path.split(sys.argv[0])[-1] myversion = 'January 4 2010' def pruneld(plinktasks=[] ,cd='./',vclbase = []): """ plink blathers when doing pruning - ignore Linkage disequilibrium based SNP pruning if a million snps in 3 billion base pairs, have mean 3k spacing assume 40-60k of ld in ceu, a window of 120k width is about 40 snps so lots more is perhaps less efficient - each window computational cost is ON^2 unless the code is smart enough to avoid unecessary computation where allele frequencies make it impossible to see ld > the r^2 cutoff threshold So, do a window and move forward 20? from the plink docs at http://pngu.mgh.harvard.edu/~purcell/plink/summary.shtml#prune Sometimes it is useful to generate a pruned subset of SNPs that are in approximate linkage equilibrium with each other. This can be achieved via two commands: --indep which prunes based on the variance inflation factor (VIF), which recursively removes SNPs within a sliding window; second, --indep-pairwise which is similar, except it is based only on pairwise genotypic correlation. Hint The output of either of these commands is two lists of SNPs: those that are pruned out and those that are not. A separate command using the --extract or --exclude option is necessary to actually perform the pruning. The VIF pruning routine is performed: plink --file data --indep 50 5 2 will create files plink.prune.in plink.prune.out Each is a simlpe list of SNP IDs; both these files can subsequently be specified as the argument for a --extract or --exclude command. The parameters for --indep are: window size in SNPs (e.g. 50), the number of SNPs to shift the window at each step (e.g. 5), the VIF threshold. The VIF is 1/(1-R^2) where R^2 is the multiple correlation coefficient for a SNP being regressed on all other SNPs simultaneously. That is, this considers the correlations between SNPs but also between linear combinations of SNPs. A VIF of 10 is often taken to represent near collinearity problems in standard multiple regression analyses (i.e. implies R^2 of 0.9). A VIF of 1 would imply that the SNP is completely independent of all other SNPs. Practically, values between 1.5 and 2 should probably be used; particularly in small samples, if this threshold is too low and/or the window size is too large, too many SNPs may be removed. The second procedure is performed: plink --file data --indep-pairwise 50 5 0.5 This generates the same output files as the first version; the only difference is that a simple pairwise threshold is used. The first two parameters (50 and 5) are the same as above (window size and step); the third parameter represents the r^2 threshold. Note: this represents the pairwise SNP-SNP metric now, not the multiple correlation coefficient; also note, this is based on the genotypic correlation, i.e. it does not involve phasing. To give a concrete example: the command above that specifies 50 5 0.5 would a) consider a window of 50 SNPs, b) calculate LD between each pair of SNPs in the window, b) remove one of a pair of SNPs if the LD is greater than 0.5, c) shift the window 5 SNPs forward and repeat the procedure. To make a new, pruned file, then use something like (in this example, we also convert the standard PED fileset to a binary one): plink --file data --extract plink.prune.in --make-bed --out pruneddata """ logres = ['## Rgenetics %s: http://rgenetics.org Galaxy Tools rgLDIndep.py Plink pruneLD runner\n' % myversion,] for task in plinktasks: # each is a list fplog,plog = tempfile.mkstemp() sto = open(plog,'w') # to catch the blather vcl = vclbase + task s = '## ldindep now executing %s\n' % ' '.join(vcl) print s logres.append(s) x = subprocess.Popen(' '.join(vcl),shell=True,stdout=sto,stderr=sto,cwd=cd) retval = x.wait() sto.close() sto = open(plog,'r') # read try: lplog = sto.readlines() lplog = [x for x in lplog if x.find('Pruning SNP') == -1] logres += lplog logres.append('\n') except: logres.append('### %s Strange - no std out from plink when running command line\n%s' % (timenow(),' '.join(vcl))) sto.close() os.unlink(plog) # no longer needed return logres def clean(): """ """ if len(sys.argv) < 14: print >> sys.stdout, '## %s expected 14 params in sys.argv, got %d - %s' % (prog,len(sys.argv),sys.argv) print >> sys.stdout, """this script will filter a linkage format ped and map file containing genotypes. It takes 14 parameters - the plink --f parameter and" a new filename root for the output clean data followed by the mind,geno,hwe,maf, mef and mei" documented in the plink docs plus the file to be returned to Galaxy Called as: <command interpreter="python"> rgLDIndep.py '$input_file.extra_files_path' '$input_file.metadata.base_name' '$title' '$mind' '$geno' '$hwe' '$maf' '$mef' '$mei' '$out_file1' '$out_file1.extra_files_path' '$window' '$step' '$r2' </command> """ sys.exit(1) plog = ['## Rgenetics: http://rgenetics.org Galaxy Tools rgLDIndep.py started %s\n' % timenow()] inpath = sys.argv[1] inbase = sys.argv[2] killme = string.punctuation + string.whitespace trantab = string.maketrans(killme,'_'*len(killme)) title = sys.argv[3].translate(trantab) mind = sys.argv[4] geno = sys.argv[5] hwe = sys.argv[6] maf = sys.argv[7] me1 = sys.argv[8] me2 = sys.argv[9] outfname = sys.argv[10] outfpath = sys.argv[11] winsize = sys.argv[12] step = sys.argv[13] r2 = sys.argv[14] output = os.path.join(outfpath,outfname) outpath = os.path.join(outfpath,title) outprunepath = os.path.join(outfpath,'ldprune_%s' % title) try: os.makedirs(outfpath) except: pass bfile = os.path.join(inpath,inbase) filterout = os.path.join(outpath,'filtered_%s' % inbase) outf = file(outfname,'w') outf.write(galhtmlprefix % prog) ldin = bfile plinktasks = [['--bfile',ldin,'--indep-pairwise %s %s %s' % (winsize,step,r2),'--out',outpath, '--mind',mind,'--geno',geno,'--maf',maf,'--hwe',hwe,'--me',me1,me2,], ['--bfile',ldin,'--extract %s.prune.in --make-bed --out %s' % (outpath,outpath)], ['--bfile',outpath,'--recode --out',outpath]] # make map file - don't really need ped but... # subset of ld independent markers for eigenstrat and other requirements vclbase = [plinke,'--noweb'] prunelog = pruneld(plinktasks=plinktasks,cd=outfpath,vclbase = vclbase) """This generates the same output files as the first version; the only difference is that a simple pairwise threshold is used. The first two parameters (50 and 5) are the same as above (window size and step); the third parameter represents the r^2 threshold. Note: this represents the pairwise SNP-SNP metric now, not the multiple correlation coefficient; also note, this is based on the genotypic correlation, i.e. it does not involve phasing. """ plog += prunelog flog = '%s.log' % outpath flogf = open(flog,'w') flogf.write(''.join(plog)) flogf.write('\n') flogf.close() globme = os.path.join(outfpath,'*') flist = glob.glob(globme) flist.sort() for i, data in enumerate( flist ): outf.write('<li><a href="%s">%s</a></li>\n' % (os.path.split(data)[-1],os.path.split(data)[-1])) outf.write('</ol></div>\n') outf.write("</div></body></html>") outf.close() if __name__ == "__main__": clean()