1 # Copyright (C) 2007-2011 Martin A. Hansen.
3 # This program is free software; you can redistribute it and/or
4 # modify it under the terms of the GNU General Public License
5 # as published by the Free Software Foundation; either version 2
6 # of the License, or (at your option) any later version.
8 # This program is distributed in the hope that it will be useful,
9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 # GNU General Public License for more details.
13 # You should have received a copy of the GNU General Public License
14 # along with this program; if not, write to the Free Software
15 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17 # http://www.gnu.org/copyleft/gpl.html
19 # >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
21 # This software is part of the Biopieces framework (www.biopieces.org).
23 # >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
25 require 'inline' # RubyInline
27 # Error class for all exceptions to do with BackTrack.
28 class BackTrackError < StandardError; end
30 # Module containing code to locate nucleotide patterns in sequences allowing for
31 # ambiguity codes and a given maximum mismatches, insertions, and deletions. The
32 # pattern match engine is based on a backtrack algorithm.
33 # Insertions are nucleotides found in the pattern but not in the sequence.
34 # Deletions are nucleotides found in the sequence but not in the pattern.
35 # Algorithm based on code kindly provided by j_random_hacker @ Stackoverflow:
36 # http://stackoverflow.com/questions/7557017/approximate-string-matching-using-backtracking/
38 OK_PATTERN = Regexp.new('^[bflsycwphqrimtnkvadegu]+$')
39 MAX_MIS = 5 # Maximum number of mismatches allowed
40 MAX_INS = 5 # Maximum number of insertions allowed
41 MAX_DEL = 5 # Maximum number of deletions allowed
43 def patmatch(pattern, offset = 0, max_mismatches = 0, max_insertions = 0, max_deletions = 0)
44 self.patscan(pattern, offset, max_mismatches, max_insertions, max_deletions) do |m|
61 # ------------------------------------------------------------------------------
62 # str.scan(pattern[, max_mismatches[, max_insertions[, max_deletions]]])
64 # str.scan(pattern[, max_mismatches[, max_insertions[, max_deletions]]]) { |match|
69 # ------------------------------------------------------------------------------
70 # Method to iterate through a sequence to locate pattern matches starting at a
71 # given offset allowing for a maximum number of mismatches, insertions, and
72 # deletions. Insertions are nucleotides found in the pattern but not in the
73 # sequence. Deletions are nucleotides found in the sequence but not in the
74 # pattern. Matches found in block context return the Match object. Otherwise
75 # matches are returned in an Array of Match objects.
76 def patscan(pattern, offset = 0, max_mismatches = 0, max_insertions = 0, max_deletions = 0)
77 raise BackTrackError, "Bad pattern: #{pattern}" unless pattern.downcase =~ OK_PATTERN
78 raise BackTrackError, "offset: #{offset} out of range (0 ... #{self.length})" unless (0 ... self.length).include? offset
79 raise BackTrackError, "max_mismatches: #{max_mismatches} out of range (0 .. #{MAX_MIS})" unless (0 .. MAX_MIS).include? max_mismatches
80 raise BackTrackError, "max_insertions: #{max_insertions} out of range (0 .. #{MAX_INS})" unless (0 .. MAX_INS).include? max_insertions
81 raise BackTrackError, "max_deletions: #{max_deletions} out of range (0 .. #{MAX_DEL})" unless (0 .. MAX_DEL).include? max_deletions
86 while result = scan_C(self.seq, self.length, pattern, offset, max_mismatches, max_insertions, max_deletions)
87 yield Match.new(result.first, result.last, self.seq[result.first ... result.first + result.last])
88 offset = result.first + 1
91 while result = scan_C(self.seq, self.length, pattern, offset, max_mismatches, max_insertions, max_deletions)
92 matches << Match.new(result.first, result.last, self.seq[result.first ... result.first + result.last])
93 offset = result.first + 1
97 return matches.empty? ? nil : matches unless block_given?
103 # Macro for matching nucleotides including ambiguity codes.
105 #define MATCH(A,B) ((bitmap[A] & bitmap[B]) != 0)
108 # Bitmap for matching nucleotides including ambiguity codes.
109 # For each value bits are set from the left: bit pos 1 for A,
110 # bit pos 2 for T, bit pos 3 for C, and bit pos 4 for G.
113 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
114 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
115 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
116 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
117 0, 1,14, 4,11, 0, 0, 8, 7, 0, 0,10, 0, 5,15, 0,
118 0, 0, 9,12, 2, 2,13, 3, 0, 6, 0, 0, 0, 0, 0, 0,
119 0, 1,14, 4,11, 0, 0, 8, 7, 0, 0,10, 0, 5,15, 0,
120 0, 0, 9,12, 2, 2,13, 3, 0, 6, 0, 0, 0, 0, 0, 0,
121 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
122 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
123 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
124 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
125 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
126 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
127 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
128 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
132 # Backtrack algorithm for matching a pattern (p) starting in a sequence (s) allowing for mis
133 # mismatches, ins insertions and del deletions. ss is the start of the sequence, used only for
134 # reporting the match endpoints. State is used to avoid ins followed by del and visa versa which
137 unsigned int backtrack(
138 char *ss, // Sequence start
141 unsigned int mis, // Max mismatches
142 unsigned int ins, // Max insertions
143 unsigned int del, // Max deletions
144 int state // Last event: mis, ins or del
149 while (*s && MATCH(*s, *p)) ++s, ++p; // OK to always match longest segment
152 return (unsigned int) (s - ss);
155 if (mis && *s && *p && (r = backtrack(ss, s + 1, p + 1, mis - 1, ins, del, 0))) return r;
156 if (ins && *p && (state != -1) && (r = backtrack(ss, s, p + 1, mis, ins - 1, del, 1))) return r;
157 if (del && *s && (state != 1) && (r = backtrack(ss, s + 1, p, mis, ins, del - 1, -1))) return r;
164 # Find pattern (p) in a sequence (s) starting at pos, with at most mis mismatches, ins
165 # insertions and del deletions.
168 VALUE _s, // Sequence
169 VALUE _len, // Sequence length
171 VALUE _pos, // Start position
172 VALUE _mis, // Maximum mismatches
173 VALUE _ins, // Maximum insertions
174 VALUE _del // Maximum deletions
177 char *s = StringValuePtr(_s);
178 char *p = StringValuePtr(_p);
179 unsigned int len = FIX2UINT(_len);
180 unsigned int pos = FIX2UINT(_pos);
181 unsigned int mis = FIX2UINT(_mis);
182 unsigned int ins = FIX2UINT(_ins);
183 unsigned int del = FIX2UINT(_del);
196 if ((e = backtrack(ss, s, p, mis, ins, del, state)))
198 tuple = rb_ary_new();
199 rb_ary_push(tuple, INT2FIX((int) (s - ss)));
200 rb_ary_push(tuple, INT2FIX((int) e - (s - ss)));
213 # Class containing match information.
215 attr_reader :pos, :length, :match
217 def initialize(pos, length, match)
224 "#{pos}:#{length}:#{match}"