comparison region_motif_compare.r @ 0:5c044273554d draft

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author jeremyjliu
date Tue, 05 Aug 2014 13:56:22 -0400
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1 # Name: region_motif_compare.r
2 # Description: Reads in two count files and determines enriched and depleted
3 # motifs (or any location based feature) based on poisson tests and gc
4 # corrections. All enrichment ratios relative to overall count / gc ratios.
5 # Author: Jeremy liu
6 # Email: jeremy.liu@yale.edu
7 # Date: 14/07/03
8 # Note: This script is meant to be invoked with the following command
9 # R --slave --vanilla -f ./region_motif_compare.r --args <workingdir> <db> <intab1> <intab2>
10 # <enriched_tab> <depleted_tab> <plots_png>
11 # <workingdir> is working directory of galaxy installation
12 # <db> types: "t" test, "p" pouya, "j" jaspar jolma, "m" mouse, "c" combined
13 # Dependencies: plotting.r
14
15 # Auxiliary function to concatenate multiple strings
16 concat <- function(...) {
17 input_list <- list(...)
18 return(paste(input_list, sep="", collapse=""))
19 }
20
21 # Supress all warning messages to prevent Galaxy treating warnings as errors
22 options(warn=-1)
23
24 # Set common and data directories
25 args <- commandArgs()
26 workingDir = args[7]
27 commonDir = concat(workingDir, "/tools/my_tools")
28 dbCode = args[8]
29 # dbCode "c" implemented when pwmFile is loaded
30 if (dbCode == "t" | dbCode == "p") {
31 pwmFile = concat(commonDir, "/region_motif_db/pwms/pouya.pwms.from.seq.RData")
32 } else if (dbCode == "j") {
33 pwmFile = concat(commonDir, "/region_motif_db/pwms/jaspar.jolma.pwms.from.seq.RData")
34 } else if (dbCode == "m") {
35 pwmFile = concat(commonDir, "/region_motif_db/pwms/mm9.pwms.from.seq.RData")
36 } else if (dbCode == "c") { # rest of dbCode "c" implemeted when pwmFile loaded
37 pwmFile = concat(commonDir, "/region_motif_db/pwms/pouya.pwms.from.seq.RData")
38 pwmFile2 = concat(commonDir, "/region_motif_db/pwms/jaspar.jolma.pwms.from.seq.RData")
39 } else {
40 pwmFile = concat(commonDir, "/region_motif_db/pwms/pouya.pwms.from.seq.RData")
41 }
42
43 # Set input and reference files
44 inTab1 = args[9]
45 inTab2 = args[10]
46 enrichTab = args[11]
47 depleteTab = args[12]
48 plotsPng = args[13]
49
50 # Load dependencies
51 source(concat(commonDir, "/region_motif_lib/plotting.r"))
52
53 # Auxiliary function to read in tab file and prepare the data
54 read_tsv <- function(file) {
55 data = read.table(file, sep="\t", stringsAsFactors=FALSE)
56 names(data)[names(data) == "V1"] = "motif"
57 names(data)[names(data) == "V2"] = "counts"
58 return(data)
59 }
60
61 startTime = Sys.time()
62 cat("Running ... Started at:", format(startTime, "%a %b %d %X %Y"), "...\n")
63
64 # Loading motif position weight matrix (pwm) file and input tab file
65 #cat("Loading and reading input region motif count files...\n")
66 load(pwmFile) # pwms data structure
67 if (dbCode == "c") { # Remaining implementation of dbCode "c" combined
68 temp = pwms
69 load(pwmFile2)
70 pwms = append(temp, pwms)
71 }
72 region1DF = read_tsv(inTab1)
73 region2DF = read_tsv(inTab2)
74 region1Counts = region1DF$counts
75 region2Counts = region2DF$counts
76 names(region1Counts) = region1DF$motif
77 names(region2Counts) = region2DF$motif
78
79 # Processing count vectors to account for missing 0 count motifs, then sorting
80 #cat("Performing 0 count correction and sorting...\n")
81 allNames = union(names(region1Counts), names(region2Counts))
82 region1Diff = setdiff(allNames, names(region1Counts))
83 region2Diff = setdiff(allNames, names(region2Counts))
84 addCounts1 = rep(0, length(region1Diff))
85 addCounts2 = rep(0, length(region2Diff))
86 names(addCounts1) = region1Diff
87 names(addCounts2) = region2Diff
88 newCounts1 = append(region1Counts, addCounts1)
89 newCounts2 = append(region2Counts, addCounts2)
90 region1Counts = newCounts1[sort.int(names(newCounts1), index.return=TRUE)$ix]
91 region2Counts = newCounts2[sort.int(names(newCounts2), index.return=TRUE)$ix]
92
93 # Generate gc content matrix
94 gc = sapply(pwms, function(i) mean(i[2:3,3:18]))
95
96 # Apply poisson test, calculate p and q values, and filter significant results
97 #cat("Applying poisson test...\n")
98 rValue = sum(region2Counts) / sum(region1Counts)
99 pValue = sapply(seq(along=region1Counts), function(i) {
100 poisson.test(c(region1Counts[i], region2Counts[i]), r=1/rValue)$p.value
101 })
102 qValue = p.adjust(pValue, "fdr")
103 indices = which(qValue<0.1 & abs(log2(region1Counts/region2Counts/rValue))>log2(1.5))
104
105 # Setting up output diagnostic plots, 4 in 1 png image
106 png(plotsPng, width=800, height=800)
107 xlab = "region1_count"
108 ylab = "region2_count"
109 lim = c(0.5, 5000)
110 layout(matrix(1:4, ncol=2))
111 par(mar=c(5, 5, 5, 1))
112
113 # Plot all motif counts along the linear correlation coefficient
114 plot.scatter(region1Counts+0.5, region2Counts+0.5, log="xy", xlab=xlab, ylab=ylab,
115 cex.lab=2.2, cex.axis=1.8, xlim=lim, ylim=lim*rValue)
116 abline(0, rValue, untf=T)
117 abline(0, rValue*2, untf=T, lty=2)
118 abline(0, rValue/2, untf=T, lty=2)
119
120 # Plot enriched and depleted motifs in red, housed in second plot
121 plot.scatter(region1Counts+0.5, region2Counts+0.5, log="xy", xlab=xlab, ylab=ylab,
122 cex.lab=2.2, cex.axis=1.8, xlim=lim, ylim=lim*rValue)
123 points(region1Counts[indices]+0.5, region2Counts[indices]+0.5, col="red")
124 abline(0, rValue, untf=T)
125 abline(0, rValue*2, untf=T, lty=2)
126 abline(0, rValue/2, untf=T, lty=2)
127
128 # Apply and plot gc correction and loess curve
129 #cat("Applying gc correction, rerunning poisson test...\n")
130 ind = which(region1Counts>5)
131 gc = gc[names(region2Counts)] # Reorder the indices of pwms to match input data
132 lo = plot.scatter(gc,log2(region2Counts/region1Counts),draw.loess=T,
133 xlab="gc content of motif",ylab=paste("log2(",ylab,"/",xlab,")"),
134 cex.lab=2.2,cex.axis=1.8,ind=ind) # This function is in plotting.r
135 gcCorrection = 2^approx(lo$loess,xout=gc,rule=2)$y
136 save(gc, file="gc.RData")
137
138 # Recalculate p and q values, and filter for significant entries
139 pValueGC = sapply(seq(along=region1Counts),function(i) {
140 poisson.test(c(region1Counts[i],region2Counts[i]),r=1/gcCorrection[i])$p.value
141 })
142 qValueGC=p.adjust(pValueGC,"fdr")
143 indicesGC = which(qValueGC<0.1 & abs(log2(region1Counts/region2Counts*gcCorrection))>log2(1.5))
144
145 # Plot gc corrected motif counts
146 plot.scatter(region1Counts+0.5, (region2Counts+0.5)/gcCorrection, log="xy",
147 xlab=xlab, ylab=paste(ylab,"(normalized)"), cex.lab=2.2, cex.axis=1.8,
148 xlim=lim, ylim=lim)
149 points(region1Counts[indicesGC]+0.5,
150 (region2Counts[indicesGC]+0.5)/gcCorrection[indicesGC], col="red")
151 abline(0,1)
152 abline(0,1*2,untf=T,lty=2)
153 abline(0,1/2,untf=T,lty=2)
154
155 # Trim results, compile statistics and output to file
156 # Only does so if significant results are computed
157 if(length(indicesGC) > 0) {
158 # Calculate expected counts and enrichment ratios
159 #cat("Calculating statistics...\n")
160 nullExpect = region1Counts * gcCorrection
161 enrichment = region2Counts / nullExpect
162
163 # Reorder selected indices in ascending pvalue
164 #cat("Reordering by ascending pvalue...\n")
165 indicesReorder = indicesGC[order(pValueGC[indicesGC])]
166
167 # Combine data into one data frame and output to two files
168 #cat("Splitting and outputting data...\n")
169 outDF = data.frame(motif=names(pValueGC), p=as.numeric(pValueGC), q=qValueGC,
170 stringsAsFactors=F, region_1_count=region1Counts,
171 null_expectation=round(nullExpect,2), region_2_count=region2Counts,
172 enrichment=enrichment)[indicesReorder,]
173 names(outDF)[which(names(outDF)=="region_1_count")]=xlab
174 names(outDF)[which(names(outDF)=="region_2_count")]=ylab
175 indicesEnrich = which(outDF$enrichment>1)
176 indicesDeplete = which(outDF$enrichment<1)
177 outDF$enrichment = ifelse(outDF$enrichment>1,
178 round(outDF$enrichment,3),
179 paste("1/",round(1/outDF$enrichment,3)))
180 write.table(outDF[indicesEnrich,], file=enrichTab, quote=FALSE,
181 sep="\t", append=FALSE, row.names=FALSE, col.names=TRUE)
182 write.table(outDF[indicesDeplete,], file=depleteTab, quote=FALSE,
183 sep="\t", append=FALSE, row.names=FALSE, col.names=TRUE)
184 }
185
186 # Catch display messages and output timing information
187 catchMessage = dev.off()
188 cat("Done. Job started at:", format(startTime, "%a %b %d %X %Y."),
189 "Job ended at:", format(Sys.time(), "%a %b %d %X %Y."), "\n")