X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=bam_mcns.c;h=d337e5a290aa76a1f1faa2c8a687db4639962a16;hb=d742c10178d8981ce062cb1f993149cfe9876613;hp=dee2016507100888faf053163ec47a8b8b474828;hpb=d763698cc12d7daa7361d610db3c9c9e83e7655b;p=samtools.git diff --git a/bam_mcns.c b/bam_mcns.c index dee2016..d337e5a 100644 --- a/bam_mcns.c +++ b/bam_mcns.c @@ -1,28 +1,37 @@ #include #include +#include #include "bam_mcns.h" #define MC_MIN_QUAL 13 +#define MC_AVG_ERR 0.007 #define MC_MAX_SUMQ 3000 #define MC_MAX_SUMQP 1e-300 +#define MC_MAX_EM_ITER 16 +#define MC_EM_EPS 1e-4 struct __mc_aux_t { - int n, N; + int n, M; int ref, alt; - double theta; double *q2p, *pdg; // pdg -> P(D|g) double *alpha, *beta; + double *z, *zswap; // aux for afs + double *afs, *afs1; // afs: accumulative AFS; afs1: site posterior distribution int *qsum, *bcnt; }; -void mc_init_prior(mc_aux_t *ma, double theta) +void mc_init_prior(mc_aux_t *ma, int type, double theta) { - double sum; int i; - ma->theta = theta; - for (i = 0, sum = 0.; i < 2 * ma->n; ++i) - sum += (ma->alpha[i] = ma->theta / (2 * ma->n - i)); - ma->alpha[2 * ma->n] = 1. - sum; + if (type == MC_PTYPE_COND2) { + for (i = 0; i <= 2 * ma->n; ++i) + ma->alpha[i] = 2. * (i + 1) / (2 * ma->n + 1) / (2 * ma->n + 2); + } else { + double sum; + for (i = 0, sum = 0.; i < 2 * ma->n; ++i) + sum += (ma->alpha[i] = theta / (2 * ma->n - i)); + ma->alpha[2 * ma->n] = 1. - sum; + } } mc_aux_t *mc_init(int n) // FIXME: assuming diploid @@ -30,23 +39,27 @@ mc_aux_t *mc_init(int n) // FIXME: assuming diploid mc_aux_t *ma; int i; ma = calloc(1, sizeof(mc_aux_t)); - ma->n = n; ma->N = 2 * n; + ma->n = n; ma->M = 2 * n; ma->q2p = calloc(MC_MAX_SUMQ + 1, sizeof(double)); ma->qsum = calloc(4 * ma->n, sizeof(int)); ma->bcnt = calloc(4 * ma->n, sizeof(int)); ma->pdg = calloc(3 * ma->n, sizeof(double)); ma->alpha = calloc(2 * ma->n + 1, sizeof(double)); ma->beta = calloc((2 * ma->n + 1) * 3, sizeof(double)); + ma->z = calloc(2 * ma->n + 1, sizeof(double)); + ma->zswap = calloc(2 * ma->n + 1, sizeof(double)); + ma->afs = calloc(2 * ma->n + 1, sizeof(double)); + ma->afs1 = calloc(2 * ma->n + 1, sizeof(double)); for (i = 0; i <= MC_MAX_SUMQ; ++i) ma->q2p[i] = pow(10., -i / 10.); - for (i = 0; i <= 2 * ma->n; ++i) { + for (i = 0; i <= ma->M; ++i) { // beta[k][g]=P(g|k/M) double *bi = ma->beta + 3 * i; - double f = (double)i / (2 * ma->n); + double f = (double)i / ma->M; bi[0] = (1. - f) * (1. - f); bi[1] = 2 * f * (1. - f); bi[2] = f * f; } - mc_init_prior(ma, 1e-3); // the simplest prior + mc_init_prior(ma, MC_PTYPE_FULL, 1e-3); // the simplest prior return ma; } @@ -56,19 +69,21 @@ void mc_destroy(mc_aux_t *ma) free(ma->qsum); free(ma->bcnt); free(ma->q2p); free(ma->pdg); free(ma->alpha); free(ma->beta); + free(ma->z); free(ma->zswap); + free(ma->afs); free(ma->afs1); free(ma); } } -static void sum_err(int *n, const bam_pileup1_t **plp, mc_aux_t *ma) +static int sum_err(int *n, const bam_pileup1_t **plp, mc_aux_t *ma) { - int i, j; + int i, j, tot = 0; memset(ma->qsum, 0, sizeof(int) * 4 * ma->n); memset(ma->bcnt, 0, sizeof(int) * 4 * ma->n); for (j = 0; j < ma->n; ++j) { - int tmp, *qsum = ma->qsum + j * 4; + int *qsum = ma->qsum + j * 4; int *bcnt = ma->bcnt + j * 4; - for (i = tmp = 0; i < n[j]; ++i) { + for (i = 0; i < n[j]; ++i) { const bam_pileup1_t *p = plp[j] + i; int q, b; if (p->is_del || (p->b->core.flag&BAM_FUNMAP)) continue; @@ -79,9 +94,10 @@ static void sum_err(int *n, const bam_pileup1_t **plp, mc_aux_t *ma) if (b > 3) continue; // N qsum[b] += q; ++bcnt[b]; - ++tmp; + ++tot; } } + return tot; } static void set_allele(int ref, mc_aux_t *ma) @@ -115,58 +131,64 @@ static void cal_pdg(mc_aux_t *ma) pdg[i] = pi[i] > MC_MAX_SUMQ? MC_MAX_SUMQP : ma->q2p[pi[i]]; } } -// return the reference allele frequency -double mc_freq0(int ref, int *n, const bam_pileup1_t **plp, mc_aux_t *ma, int *_ref, int *alt) +// this calculates the naive allele frequency and Nielsen's frequency +static double mc_freq0(const mc_aux_t *ma, double *_f) { int i, cnt; - double f; - sum_err(n, plp, ma); - set_allele(ref, ma); - cal_pdg(ma); - *_ref = ma->ref; *alt = ma->alt; - for (i = cnt = 0, f = 0.; i < ma->n; ++i) { + double f, f_nielsen, w_sum; + *_f = -1.; + for (i = cnt = 0, f = f_nielsen = w_sum = 0.; i < ma->n; ++i) { int *bcnt = ma->bcnt + i * 4; int x = bcnt[ma->ref] + bcnt[ma->alt]; if (x) { + double w, p; ++cnt; f += (double)bcnt[ma->ref] / x; + p = (bcnt[ma->ref] - MC_AVG_ERR * x) / (1. - 2. * MC_AVG_ERR) / x; + w = 2. * x / (1. + x); + w_sum += w; + f_nielsen += p * w; } } - return f / cnt; + if (cnt) { + f_nielsen /= w_sum; + if (f_nielsen < 0.) f_nielsen = 0.; + if (f_nielsen > 1.) f_nielsen = 1.; + *_f = f_nielsen; + return f / cnt; + } else return -1.; } // f0 is the reference allele frequency -double mc_freq_iter(double f0, mc_aux_t *ma) +static double mc_freq_iter(double f0, const mc_aux_t *ma) { double f, f3[3]; - int i, j; + int i; f3[0] = (1.-f0)*(1.-f0); f3[1] = 2.*f0*(1.-f0); f3[2] = f0*f0; for (i = 0, f = 0.; i < ma->n; ++i) { - double up, dn, *pdg; + double *pdg; pdg = ma->pdg + i * 3; - for (j = 1, up = 0.; j < 3; ++j) - up += j * pdg[j] * f3[j]; - for (j = 0, dn = 0.; j < 3; ++j) - dn += pdg[j] * f3[j]; - f += up / dn; + f += (pdg[1] * f3[1] + 2. * pdg[2] * f3[2]) + / (pdg[0] * f3[0] + pdg[1] * f3[1] + pdg[2] * f3[2]); } f /= ma->n * 2.; return f; } -double mc_ref_prob(mc_aux_t *ma) +static double mc_ref_prob(const mc_aux_t *ma, double *_PD, double *f_exp) { - int k, i, g; - long double PD = 0., Pref = 0.; - for (k = 0; k <= ma->n * 2; ++k) { - long double x = 1.; + int k, i; + long double PD = 0., Pref = 0., Ef = 0.; + for (k = 0; k <= ma->M; ++k) { + long double x = 1., y = 0.; double *bk = ma->beta + k * 3; for (i = 0; i < ma->n; ++i) { - double y = 0., *pdg = ma->pdg + i * 3; - for (g = 0; g < 3; ++g) - y += pdg[g] * bk[g]; - x *= y; + double *pdg = ma->pdg + i * 3; + double z = pdg[0] * bk[0] + pdg[1] * bk[1] + pdg[2] * bk[2]; + x *= z; + y += (pdg[1] * bk[1] + 2. * pdg[2] * bk[2]) / z; } PD += x * ma->alpha[k]; + Ef += x * y * ma->alpha[k]; } for (k = 0; k <= ma->n * 2; ++k) { long double x = 1.0; @@ -174,6 +196,8 @@ double mc_ref_prob(mc_aux_t *ma) x *= ma->pdg[i * 3 + 2] * ma->beta[k * 3 + 2]; Pref += x * ma->alpha[k]; } + *f_exp = (double)(Ef / PD / ma->M); + *_PD = PD; return Pref / PD; } @@ -195,3 +219,91 @@ int mc_call_gt(const mc_aux_t *ma, double f0, int k) if (q > 99) q = 99; return q<<2|max_i; } +// calculate z_{nr}^{(k)} +static void mc_cal_z(mc_aux_t *ma, int k) +{ + double *z[2], *tmp, *bk, *pdg; + int i, j; + z[0] = ma->z; + z[1] = ma->zswap; + bk = ma->beta + k * 3; pdg = ma->pdg; + z[0][0] = 1.; z[0][1] = z[0][2] = 0.; + for (j = 0; j < ma->n; ++j) { + int max = (j + 1) * 2; + double p[3]; + pdg = ma->pdg + j * 3; + p[0] = bk[0] * pdg[0]; p[1] = bk[1] * pdg[1]; p[2] = bk[2] * pdg[2]; + z[1][0] = p[0] * z[0][0]; + z[1][1] = p[0] * z[0][1] + p[1] * z[0][0]; + for (i = 2; i <= max; ++i) + z[1][i] = p[0] * z[0][i] + p[1] * z[0][i-1] + p[2] * z[0][i-2]; + if (j < ma->n - 1) z[1][max+1] = z[1][max+2] = 0.; + tmp = z[0]; z[0] = z[1]; z[1] = tmp; + } + if (z[0] != ma->z) memcpy(ma->z, z[0], sizeof(double) * (2 * ma->n + 1)); +} +// Warning: this is cubic in ma->n, very sloooooow +static void mc_add_afs(mc_aux_t *ma, double PD, double *f_map, double *p_map) +{ + int k, l; + double sum = 0.; + memset(ma->afs1, 0, sizeof(double) * (2 * ma->n + 1)); + for (k = 0; k <= 2 * ma->n; ++k) { + mc_cal_z(ma, k); + for (l = 0; l <= 2 * ma->n; ++l) + ma->afs1[l] += ma->alpha[k] * ma->z[l] / PD; + } + for (k = 0; k <= 2 * ma->n; ++k) { + ma->afs[k] += ma->afs1[k]; + sum += ma->afs1[k]; + } + { + int max_k = 0; + double max = -1., e = 0.; + for (k = 0; k <= 2 * ma->n; ++k) { + if (ma->afs1[k] > max) max = ma->afs1[k], max_k = k; + e += k * ma->afs1[k]; + } + *f_map = .5 * max_k / ma->n; *p_map = max; // e should equal mc_rst_t::f_exp +// printf(" * %.3lg:%.3lg:%.3lg:%.3lg * ", sum, 1.-.5*max_k/ma->n, max, 1.-.5*e/ma->n); + } +} + +int mc_cal(int ref, int *n, const bam_pileup1_t **plp, mc_aux_t *ma, mc_rst_t *rst, int level) +{ + int i, tot; + memset(rst, 0, sizeof(mc_rst_t)); + rst->f_em = rst->f_exp = -1.; rst->ref = rst->alt = -1; + // precalculation + tot = sum_err(n, plp, ma); + if (tot == 0) return 0; // no good bases + set_allele(ref, ma); + cal_pdg(ma); + // set ref/major allele + rst->ref = ma->ref; rst->alt = ma->alt; + // calculate naive and Nielsen's freq + rst->f_naive = mc_freq0(ma, &rst->f_nielsen); + { // calculate f_em + double flast = rst->f_naive; + for (i = 0; i < MC_MAX_EM_ITER; ++i) { + rst->f_em = mc_freq_iter(flast, ma); + if (fabs(rst->f_em - flast) < MC_EM_EPS) break; + flast = rst->f_em; + } + } + if (level >= 2) // quadratic-time calculations; necessary for genotyping + rst->p_ref = mc_ref_prob(ma, &rst->PD, &rst->f_exp); + if (level >= 3) + mc_add_afs(ma, rst->PD, &rst->f_map, &rst->p_map); + return tot; +} + +void mc_dump_afs(mc_aux_t *ma) +{ + int k; + fprintf(stderr, "[afs]"); + for (k = 0; k <= ma->M; ++k) + fprintf(stderr, " %d:%.3lf", k, ma->afs[ma->M - k]); + fprintf(stderr, "\n"); + memset(ma->afs, 0, sizeof(double) * (ma->M + 1)); +}