From: martinahansen <martinahansen@74ccb610-7750-0410-82ae-013aeee3265d>
Date: Tue, 10 Apr 2012 18:08:36 +0000 (+0000)
Subject: making changes to accomodate Illumina18 qual scores
X-Git-Url: https://git.donarmstrong.com/?a=commitdiff_plain;h=acc00ae480f88bfd38b1ebd60cae966130c3ddeb;p=biopieces.git

making changes to accomodate Illumina18 qual scores

git-svn-id: http://biopieces.googlecode.com/svn/trunk@1784 74ccb610-7750-0410-82ae-013aeee3265d
---

diff --git a/code_ruby/lib/maasha/align.rb b/code_ruby/lib/maasha/align.rb
index cdab55b..32532fe 100755
--- a/code_ruby/lib/maasha/align.rb
+++ b/code_ruby/lib/maasha/align.rb
@@ -223,7 +223,7 @@ class Align
     def na_add_entries
       @entries.each_with_index do |entry, i|
         @na_seq[true, i]  = NArray.to_na(entry.seq.downcase.tr(TR_NUC, TR_HEX), "byte")
-        @na_qual[true, i] = NArray.to_na(entry.qual, "byte") - SCORE_ILLUMINA if @has_qual
+        @na_qual[true, i] = NArray.to_na(entry.qual, "byte") - SCORE_BASE if @has_qual
       end
     end
 
@@ -336,7 +336,7 @@ class Align
 
     # Method to calculate a consensus quality from a Consensus object.
     def consensus_qual
-      (@na_qual.mean(1).round.to_type("byte") + SCORE_ILLUMINA).to_s
+      (@na_qual.mean(1).round.to_type("byte") + SCORE_BASE).to_s
     end
   end
 end
diff --git a/code_ruby/lib/maasha/seq.rb b/code_ruby/lib/maasha/seq.rb
index e4b0a94..2382218 100644
--- a/code_ruby/lib/maasha/seq.rb
+++ b/code_ruby/lib/maasha/seq.rb
@@ -36,10 +36,9 @@ PROTEIN = %w[f l s y c w p h q r i m t n k v a d e g]
 INDELS  = %w[. - _ ~]
 
 # Quality scores bases
-SCORE_PHRED    = 33
-SCORE_ILLUMINA = 64
-SCORE_MIN      = 0
-SCORE_MAX      = 40
+SCORE_BASE = 64
+SCORE_MIN  = 0
+SCORE_MAX  = 40
 
 # Error class for all exceptions to do with Seq.
 class SeqError < StandardError; end
@@ -361,7 +360,7 @@ class Seq
     raise SeqError, "no quality score" if self.qual.nil?
     raise SeqError, "minimum value: #{min} out of range #{SCORE_MIN} .. #{SCORE_MAX}" unless (SCORE_MIN .. SCORE_MAX).include? min
 
-    regex_right = Regexp.new("[#{(SCORE_ILLUMINA).chr}-#{(SCORE_ILLUMINA + min).chr}]+$")
+    regex_right = Regexp.new("[#{(SCORE_BASE).chr}-#{(SCORE_BASE + min).chr}]+$")
 
     self.qual.match(regex_right) do |m|
       self.subseq!(0, $`.length) if $`.length > 0
@@ -375,7 +374,7 @@ class Seq
     raise SeqError, "no quality score" if self.qual.nil?
     raise SeqError, "minimum value: #{min} out of range #{SCORE_MIN} .. #{SCORE_MAX}" unless (SCORE_MIN .. SCORE_MAX).include? min
 
-    regex_left  = Regexp.new("^[#{(SCORE_ILLUMINA).chr}-#{(SCORE_ILLUMINA + min).chr}]+")
+    regex_left  = Regexp.new("^[#{(SCORE_BASE).chr}-#{(SCORE_BASE + min).chr}]+")
 
     self.qual.match(regex_left) do |m|
       self.subseq!(m.to_s.length, self.length - m.to_s.length) if self.length - m.to_s.length > 0
@@ -440,7 +439,7 @@ class Seq
     i      = 0
 
     scores.each_char do |score|
-      seq[i] = 'N' if score.ord - SCORE_ILLUMINA < cutoff
+      seq[i] = 'N' if score.ord - SCORE_BASE < cutoff
       i += 1 
     end
 
@@ -456,7 +455,7 @@ class Seq
 
     na_seq  = NArray.to_na(self.seq, "byte")
     na_qual = NArray.to_na(self.qual, "byte")
-    mask    = (na_qual - SCORE_ILLUMINA) < cutoff
+    mask    = (na_qual - SCORE_BASE) < cutoff
     mask   *= na_seq.ne("-".ord)
 
     na_seq[mask] = 'N'.ord
@@ -475,7 +474,7 @@ class Seq
 
     na_seq  = NArray.to_na(self.seq, "byte")
     na_qual = NArray.to_na(self.qual, "byte")
-    mask    = (na_qual - SCORE_ILLUMINA) < cutoff
+    mask    = (na_qual - SCORE_BASE) < cutoff
     mask   *= na_seq.ne("-".ord)
 
     na_seq[mask] ^= ' '.ord
@@ -485,39 +484,38 @@ class Seq
     self
   end
 
-  # Method to convert the quality scores from a specified base
-  # to another base.
-  def convert_phred2illumina!
-    self.qual.gsub!(/./) do |score|
-      score_phred  = score.ord - SCORE_PHRED
-      raise SeqError, "Bad Phred score: #{score} (#{score_phred})" unless (0 .. 41).include? score_phred
-      score_illumina = score_phred + SCORE_ILLUMINA
-      score          = score_illumina.chr
-    end
-  end
+  # Method to convert quality scores inbetween formats.
+  # Sanger     base 33, range  0-40 
+  # Solexa     base 64, range -5-40 
+  # Illumina13 base 64, range  0-40 
+  # Illumina15 base 64, range  3-40 
+  # Illumina18 base 33, range  0-41 
+  def convert_scores!(from, to)
+    unless from == to
+      na_qual = NArray.to_na(self.qual, "byte")
 
-  # Method to convert the quality scores from Solexa odd/ratio to
-  # Illumina format.
-  def convert_solexa2illumina!
-    self.qual.gsub!(/./) do |score|
-      score = solexa_char2illumina_char(score)
-    end
-  end
+      case from.downcase
+      when "sanger"     then na_qual -= 33
+      when "solexa"     then na_qual -= 64
+      when "illumina13" then na_qual -= 64
+      when "illumina15" then na_qual -= 64
+      when "illumina18" then na_qual -= 33
+      else raise SeqError, "unknown quality score encoding: #{from}"
+      end
 
-  private
+      case to.downcase
+      when "sanger"     then na_qual += 33
+      when "solexa"     then na_qual += 64
+      when "illumina13" then na_qual += 64
+      when "illumina15" then na_qual += 64
+      when "illumina18" then na_qual += 33
+      else raise SeqError, "unknown quality score encoding: #{from}"
+      end
 
-  # Method to convert a Solexa score (odd ratio) to
-  # a phred (probability) integer score.
-  def solexa2phred(score)
-    (10.0 * Math.log(10.0 ** (score / 10.0) + 1.0, 10)).to_i
-  end
+      self.qual = na_qual.to_s
+    end
 
-  # Method to convert a Solexa score encoded using base
-  # 64 ASCII to a Phred score encoded using base 64 ASCII.
-  def solexa_char2illumina_char(char)
-    score_solexa = char.ord - 64
-    score_phred  = solexa2phred(score_solexa)
-    (score_phred + 64).chr
+    self
   end
 end