# Install bcftools, its manpage, bcf-fix.pl, vcfutils.pl, and new examples.
[samtools.git] / kaln.c
diff --git a/kaln.c b/kaln.c
index 9fa40d0be3999e66b885486d7a03e50994bfbfdd..680779113ce7c2220434727cf578845d1e840d40 100644 (file)
--- a/kaln.c
+++ b/kaln.c
@@ -27,6 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdint.h>
+#include <math.h>
 #include "kaln.h"
 
 #define FROM_M 0
@@ -72,8 +73,8 @@ int aln_sm_blast[] = {
        -2, -2, -2, -2, -2
 };
 
-ka_param_t ka_param_blast = {  5,  2,  2, aln_sm_blast, 5, 50 };
-ka_param_t ka_param_aa2aa = { 10,  2,  2, aln_sm_blosum62, 22, 50 };
+ka_param_t ka_param_blast = {  5,  2,   5, 2, aln_sm_blast, 5, 50 };
+ka_param_t ka_param_aa2aa = { 10,  2,  10, 2, aln_sm_blosum62, 22, 50 };
 
 static uint32_t *ka_path2cigar32(const path_t *path, int path_len, int *n_cigar)
 {
@@ -141,13 +142,13 @@ static uint32_t *ka_path2cigar32(const path_t *path, int path_len, int *n_cigar)
 }
 #define set_end_I(II, cur, p)                                                  \
 {                                                                                                              \
-       if (gap_end >= 0) {                                                                     \
-               if ((p)->M - gap_open > (p)->I) {                               \
+       if (gap_end_ext >= 0) {                                                         \
+               if ((p)->M - gap_end_open > (p)->I) {                   \
                        (cur)->It = FROM_M;                                                     \
-                       (II) = (p)->M - gap_open - gap_end;                     \
+                       (II) = (p)->M - gap_end_open - gap_end_ext;     \
                } else {                                                                                \
                        (cur)->It = FROM_I;                                                     \
-                       (II) = (p)->I - gap_end;                                        \
+                       (II) = (p)->I - gap_end_ext;                            \
                }                                                                                               \
        } else set_I(II, cur, p);                                                       \
 }
@@ -163,13 +164,13 @@ static uint32_t *ka_path2cigar32(const path_t *path, int path_len, int *n_cigar)
 }
 #define set_end_D(DD, cur, p)                                                  \
 {                                                                                                              \
-       if (gap_end >= 0) {                                                                     \
-               if ((p)->M - gap_open > (p)->D) {                               \
+       if (gap_end_ext >= 0) {                                                         \
+               if ((p)->M - gap_end_open > (p)->D) {                   \
                        (cur)->Dt = FROM_M;                                                     \
-                       (DD) = (p)->M - gap_open - gap_end;                     \
+                       (DD) = (p)->M - gap_end_open - gap_end_ext;     \
                } else {                                                                                \
                        (cur)->Dt = FROM_D;                                                     \
-                       (DD) = (p)->D - gap_end;                                        \
+                       (DD) = (p)->D - gap_end_ext;                            \
                }                                                                                               \
        } else set_D(DD, cur, p);                                                       \
 }
@@ -195,13 +196,14 @@ uint32_t *ka_global_core(uint8_t *seq1, int len1, uint8_t *seq2, int len2, const
        uint8_t type, ctype;
        uint32_t *cigar = 0;
 
-       int gap_open, gap_ext, gap_end, b;
+       int gap_open, gap_ext, gap_end_open, gap_end_ext, b;
        int *score_matrix, N_MATRIX_ROW;
 
        /* initialize some align-related parameters. just for compatibility */
        gap_open = ap->gap_open;
        gap_ext = ap->gap_ext;
-       gap_end = ap->gap_end;
+       gap_end_open = ap->gap_end_open;
+       gap_end_ext = ap->gap_end_ext;
        b = ap->band_width;
        score_matrix = ap->matrix;
        N_MATRIX_ROW = ap->row;
@@ -368,3 +370,212 @@ uint32_t *ka_global_core(uint8_t *seq1, int len1, uint8_t *seq2, int len2, const
 
        return cigar;
 }
+
+/*****************************************
+ * Probabilistic banded glocal alignment *
+ *****************************************/
+
+static float g_qual2prob[256];
+
+#define EI .25
+#define EM .3333333333333
+#define set_u(u, b, i, k) { int x=(i)-(b); x=x>0?x:0; (u)=((k)-x+1)*3; }
+
+ka_probpar_t ka_probpar_def = { 0.001, 0.1, 10 };
+
+/*
+  The topology of the profile HMM:
+
+           /\             /\        /\             /\
+           I[1]           I[k-1]    I[k]           I[L]
+            ^   \      \    ^    \   ^   \      \   ^
+            |    \      \   |     \  |    \      \  |
+    M[0]   M[1] -> ... -> M[k-1] -> M[k] -> ... -> M[L]   M[L+1]
+                \      \/        \/      \/      /
+                 \     /\        /\      /\     /
+                       -> D[k-1] -> D[k] ->
+
+   M[0] points to every {M,I}[k] and every {M,I}[k] points M[L+1].
+
+   On input, _ref is the reference sequence and _query is the query
+   sequence. Both are sequences of 0/1/2/3/4 where 4 stands for an
+   ambiguous residue. iqual is the base quality. c sets the gap open
+   probability, gap extension probability and band width.
+
+   On output, state and q are arrays of length l_query. The higher 30
+   bits give the reference position the query base is matched to and the
+   lower two bits can be 0 (an alignment match) or 1 (an
+   insertion). q[i] gives the phred scaled posterior probability of
+   state[i] being wrong.
+ */
+int ka_prob_glocal(const uint8_t *_ref, int l_ref, const uint8_t *_query, int l_query, const uint8_t *iqual,
+                                  const ka_probpar_t *c, int *state, uint8_t *q)
+{
+       double **f, **b, *s, m[9], sI, sM, bI, bM, pb;
+       float *qual, *_qual;
+       const uint8_t *ref, *query;
+       int bw, bw2, i, k, is_diff = 0;
+
+       /*** initialization ***/
+       ref = _ref - 1; query = _query - 1; // change to 1-based coordinate
+       bw = l_ref > l_query? l_ref : l_query;
+       if (bw > c->bw) bw = c->bw;
+       if (bw < abs(l_ref - l_query)) bw = abs(l_ref - l_query);
+       bw2 = bw * 2 + 1;
+       // allocate the forward and backward matrices f[][] and b[][] and the scaling array s[]
+       f = calloc(l_query+1, sizeof(void*));
+       b = calloc(l_query+1, sizeof(void*));
+       for (i = 0; i <= l_query; ++i) {
+               f[i] = calloc(bw2 * 3 + 6, sizeof(double)); // FIXME: this is over-allocated for very short seqs
+               b[i] = calloc(bw2 * 3 + 6, sizeof(double));
+       }
+       s = calloc(l_query+2, sizeof(double)); // s[] is the scaling factor to avoid underflow
+       // initialize qual
+       _qual = calloc(l_query, sizeof(float));
+       if (g_qual2prob[0] == 0)
+               for (i = 0; i < 256; ++i)
+                       g_qual2prob[i] = pow(10, -i/10.);
+       for (i = 0; i < l_query; ++i) _qual[i] = g_qual2prob[iqual? iqual[i] : 30];
+       qual = _qual - 1;
+       // initialize transition probability
+       sM = sI = 1. / (2 * l_query + 2); // the value here seems not to affect results; FIXME: need proof
+       m[0*3+0] = (1 - c->d - c->d) * (1 - sM); m[0*3+1] = m[0*3+2] = c->d * (1 - sM);
+       m[1*3+0] = (1 - c->e) * (1 - sI); m[1*3+1] = c->e * (1 - sI); m[1*3+2] = 0.;
+       m[2*3+0] = 1 - c->e; m[2*3+1] = 0.; m[2*3+2] = c->e;
+       bM = (1 - c->d) / l_query; bI = c->d / l_query; // (bM+bI)*l_query==1
+       /*** forward ***/
+       // f[0]
+       set_u(k, bw, 0, 0);
+       f[0][k] = s[0] = 1.;
+       { // f[1]
+               double *fi = f[1], sum;
+               int beg = 1, end = l_ref < bw + 1? l_ref : bw + 1, _beg, _end;
+               for (k = beg, sum = 0.; k <= end; ++k) {
+                       int u;
+                       double e = (ref[k] > 3 || query[1] > 3)? 1. : ref[k] == query[1]? 1. - qual[1] : qual[1] * EM;
+                       set_u(u, bw, 1, k);
+                       fi[u+0] = e * bM; fi[u+1] = EI * bI;
+                       sum += fi[u] + fi[u+1];
+               }
+               // rescale
+               s[1] = sum;
+               set_u(_beg, bw, 1, beg); set_u(_end, bw, 1, end); _end += 2;
+               for (k = _beg; k <= _end; ++k) fi[k] /= sum;
+       }
+       // f[2..l_query]
+       for (i = 2; i <= l_query; ++i) {
+               double *fi = f[i], *fi1 = f[i-1], sum, qli = qual[i];
+               int beg = 1, end = l_ref, x, _beg, _end;
+               uint8_t qyi = query[i];
+               x = i - bw; beg = beg > x? beg : x; // band start
+               x = i + bw; end = end < x? end : x; // band end
+               for (k = beg, sum = 0.; k <= end; ++k) {
+                       int u, v11, v01, v10;
+                       double e;
+                       e = (ref[k] > 3 || qyi > 3)? 1. : ref[k] == qyi? 1. - qli : qli * EM;
+                       set_u(u, bw, i, k); set_u(v11, bw, i-1, k-1); set_u(v10, bw, i-1, k); set_u(v01, bw, i, k-1);
+                       fi[u+0] = e * (m[0] * fi1[v11+0] + m[3] * fi1[v11+1] + m[6] * fi1[v11+2]);
+                       fi[u+1] = EI * (m[1] * fi1[v10+0] + m[4] * fi1[v10+1]);
+                       fi[u+2] = m[2] * fi[v01+0] + m[8] * fi[v01+2];
+                       sum += fi[u] + fi[u+1] + fi[u+2];
+//                     fprintf(stderr, "F (%d,%d;%d): %lg,%lg,%lg\n", i, k, u, fi[u], fi[u+1], fi[u+2]); // DEBUG
+               }
+               // rescale
+               s[i] = sum;
+               set_u(_beg, bw, i, beg); set_u(_end, bw, i, end); _end += 2;
+               for (k = _beg, sum = 1./sum; k <= _end; ++k) fi[k] *= sum;
+       }
+       { // f[l_query+1]
+               double sum;
+               for (k = 1, sum = 0.; k <= l_ref; ++k) {
+                       int u;
+                       set_u(u, bw, l_query, k);
+                       if (u < 3 || u >= bw2*3+3) continue;
+                   sum += f[l_query][u+0] * sM + f[l_query][u+1] * sI;
+               }
+               s[l_query+1] = sum; // the last scaling factor
+       }
+       /*** backward ***/
+       // b[l_query] (b[l_query+1][0]=1 and thus \tilde{b}[][]=1/s[l_query+1]; this is where s[l_query+1] comes from)
+       for (k = 1; k <= l_ref; ++k) {
+               int u;
+               double *bi = b[l_query];
+               set_u(u, bw, l_query, k);
+               if (u < 3 || u >= bw2*3+3) continue;
+               bi[u+0] = sM / s[l_query] / s[l_query+1]; bi[u+1] = sI / s[l_query] / s[l_query+1];
+       }
+       // b[l_query-1..1]
+       for (i = l_query - 1; i >= 1; --i) {
+               int beg = 1, end = l_ref, x, _beg, _end;
+               double *bi = b[i], *bi1 = b[i+1], y = (i > 1), qli1 = qual[i+1];
+               uint8_t qyi1 = query[i+1];
+               x = i - bw; beg = beg > x? beg : x;
+               x = i + bw; end = end < x? end : x;
+               for (k = end; k >= beg; --k) {
+                       int u, v11, v01, v10;
+                       double e;
+                       set_u(u, bw, i, k); set_u(v11, bw, i+1, k+1); set_u(v10, bw, i+1, k); set_u(v01, bw, i, k+1);
+                       e = (k >= l_ref? 0 : (ref[k+1] > 3 || qyi1 > 3)? 1. : ref[k+1] == qyi1? 1. - qli1 : qli1 * EM) * bi1[v11];
+                       bi[u+0] = e * m[0] + EI * m[1] * bi1[v10+1] + m[2] * bi[v01+2]; // bi1[v11] has been foled into e.
+                       bi[u+1] = e * m[3] + EI * m[4] * bi1[v10+1];
+                       bi[u+2] = (e * m[6] + m[8] * bi[v01+2]) * y;
+//                     fprintf(stderr, "B (%d,%d;%d): %lg,%lg,%lg\n", i, k, u, bi[u], bi[u+1], bi[u+2]); // DEBUG
+               }
+               // rescale
+               set_u(_beg, bw, i, beg); set_u(_end, bw, i, end); _end += 2;
+               for (k = _beg, y = 1./s[i]; k <= _end; ++k) bi[k] *= y;
+       }
+       { // b[0]
+               int beg = 1, end = l_ref < bw + 1? l_ref : bw + 1;
+               double sum = 0.;
+               for (k = end; k >= beg; --k) {
+                       int u;
+                       double e = (ref[k] > 3 || query[1] > 3)? 1. : ref[k] == query[1]? 1. - qual[1] : qual[1] * EM;
+                       set_u(u, bw, 1, k);
+                       if (u < 3 || u >= bw2*3+3) continue;
+                   sum += e * b[1][u+0] * bM + EI * b[1][u+1] * bI;
+               }
+               set_u(k, bw, 0, 0);
+               pb = b[0][k] = sum / s[0]; // if everything works as is expected, pb == 1.0
+       }
+       is_diff = fabs(pb - 1.) > 1e-7? 1 : 0;
+       /*** MAP ***/
+       for (i = 1; i <= l_query; ++i) {
+               double sum = 0., *fi = f[i], *bi = b[i], max = 0.;
+               int beg = 1, end = l_ref, x, max_k = -1;
+               x = i - bw; beg = beg > x? beg : x;
+               x = i + bw; end = end < x? end : x;
+               for (k = beg; k <= end; ++k) {
+                       int u;
+                       double z;
+                       set_u(u, bw, i, k);
+                       z = fi[u+0] * bi[u+0]; if (z > max) max = z, max_k = (k-1)<<2 | 0; sum += z;
+                       z = fi[u+1] * bi[u+1]; if (z > max) max = z, max_k = (k-1)<<2 | 1; sum += z;
+               }
+               max /= sum; sum *= s[i]; // if everything works as is expected, sum == 1.0
+               if (state) state[i-1] = max_k;
+               if (q) k = (int)(-4.343 * log(1. - max) + .499), q[i-1] = k > 100? 99 : k;
+#ifdef _MAIN
+               fprintf(stderr, "(%.10lg,%.10lg) (%d,%d:%d)~%lg\n", pb, sum, i-1, max_k>>2, max_k&3, max); // DEBUG
+#endif
+       }
+       /*** free ***/
+       for (i = 0; i <= l_query; ++i) {
+               free(f[i]); free(b[i]);
+       }
+       free(f); free(b); free(s); free(_qual);
+       return 0;
+}
+
+#ifdef _MAIN
+int main()
+{
+       int l_ref = 5, l_query = 4;
+       uint8_t *ref = (uint8_t*)"\0\1\3\3\1";
+       uint8_t *query = (uint8_t*)"\0\3\3\1";
+//     uint8_t *query = (uint8_t*)"\1\3\3\1";
+       static uint8_t qual[4] = {20, 20, 20, 20};
+       ka_prob_glocal(ref, l_ref, query, l_query, qual, &ka_probpar_def, 0, 0);
+       return 0;
+}
+#endif