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 # >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
27 # Module containing code to locate nucleotide patterns in sequences allowing for
28 # ambiguity codes and a given maximum mismatches, insertions, and deletions. The
29 # pattern match engine is based on a backtrack algorithm.
31 # ------------------------------------------------------------------------------
32 # str.scan(pattern[, max_mismatches [, max_insertions [,max_deletions]]])
34 # str.scan(pattern[, max_mismatches [, max_insertions [,max_deletions]]]) { |match|
39 # ------------------------------------------------------------------------------
40 # Method to iterate through a sequence to locate pattern matches starting at a
41 # given offset allowing for a maximum number of mismatches, insertions, and
42 # deletions. Matches found in block context return the Match object. Otherwise
43 # matches are returned in an Array of Match objects.
44 def patscan(pattern, offset = 0, max_mismatches = 0, max_insertions = 0, max_deletions = 0)
48 while result = self.track(pattern, offset, max_mismatches, max_insertions, max_deletions)
49 yield Match.new(result.first, result.last, self.seq[result.first ... result.first + result.last])
50 offset = result.first + 1
53 while result = self.track(pattern, offset, max_mismatches, max_insertions, max_deletions)
54 matches << Match.new(result.first, result.last, self.seq[result.first ... result.first + result.last])
55 offset = result.first + 1
59 return matches.empty? ? nil : matches unless block_given?
65 builder.add_static "id_seq", 'rb_intern("@seq")', "ID"
68 #define MATCH(A,B) ((bitmap[(unsigned short) A] & bitmap[(unsigned short) B]) != 0)
72 unsigned short bitmap[256] = {
73 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
74 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
75 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
76 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
77 0, 1,14, 4,11, 0, 0, 8, 7, 0, 0,10, 0, 5,15, 0,
78 0, 0, 9,12, 2, 2,13, 3, 0, 6, 0, 0, 0, 0, 0, 0,
79 0, 1,14, 4,11, 0, 0, 8, 7, 0, 0,10, 0, 5,15, 0,
80 0, 0, 9,12, 2, 2,13, 3, 0, 6, 0, 0, 0, 0, 0, 0,
81 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
82 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
83 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
84 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
85 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
86 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
87 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
88 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
92 # ss is the start of the string, used only for reporting the match endpoints.
94 unsigned int backtrack(char* ss, char* s, char* p, int mm, int ins, int del)
98 while (*s && MATCH(*s, *p)) ++s, ++p; // OK to always match longest segment
101 return (unsigned int) (s - ss);
104 if (mm && *s && *p && (r = backtrack(ss, s + 1, p + 1, mm - 1, ins, del))) return r;
105 if (ins && *s && (r = backtrack(ss, s + 1, p, mm, ins - 1, del))) return r;
106 if (del && *p && (r = backtrack(ss, s, p + 1, mm, ins, del - 1))) return r;
113 # Find all occurrences of p starting at pos in s, with at most
114 # mm mismatches, ins insertions and del deletions.
116 static VALUE track(char* p, int pos, int mm, int ins, int del)
118 VALUE seq = rb_ivar_get(self, id_seq);
119 char* s = StringValuePtr(seq);
124 while (*s && pos) ++s, --pos; // Fast forward until pos
128 e = backtrack(ss, s, p, mm, ins, del);
132 tuple = rb_ary_new();
133 rb_ary_push(tuple, INT2FIX((int) (s - ss)));
134 rb_ary_push(tuple, INT2FIX((int) e - (s - ss)));
145 attr_reader :pos, :length, :match
147 def initialize(pos, length, match)
154 "#{pos}:#{length}:#{match}"