|
| 1 | +""" |
| 2 | +Tests for genotype imputation (forward and Baum-Welsh algorithms). |
| 3 | +""" |
| 4 | +import io |
| 5 | + |
| 6 | +import numpy as np |
| 7 | + |
| 8 | +import _tskit |
| 9 | +import tskit |
| 10 | + |
| 11 | + |
| 12 | +# A toy tree sequence containing 3 diploid individuals with 5 sites and 5 mutations. |
| 13 | +# Two toy query haplotypes are targets for imputation. |
| 14 | + |
| 15 | +toy_ts_nodes_text = """\ |
| 16 | +id is_sample time population individual metadata |
| 17 | +0 1 0.000000 0 0 |
| 18 | +1 1 0.000000 0 0 |
| 19 | +2 1 0.000000 0 1 |
| 20 | +3 1 0.000000 0 1 |
| 21 | +4 1 0.000000 0 2 |
| 22 | +5 1 0.000000 0 2 |
| 23 | +6 0 0.029768 0 -1 |
| 24 | +7 0 0.133017 0 -1 |
| 25 | +8 0 0.223233 0 -1 |
| 26 | +9 0 0.651586 0 -1 |
| 27 | +10 0 0.698831 0 -1 |
| 28 | +11 0 2.114867 0 -1 |
| 29 | +12 0 4.322031 0 -1 |
| 30 | +13 0 7.432311 0 -1 |
| 31 | +""" |
| 32 | + |
| 33 | +toy_ts_edges_text = """\ |
| 34 | +left right parent child metadata |
| 35 | +0.000000 1000000.000000 6 0 |
| 36 | +0.000000 1000000.000000 6 3 |
| 37 | +0.000000 1000000.000000 7 2 |
| 38 | +0.000000 1000000.000000 7 5 |
| 39 | +0.000000 1000000.000000 8 1 |
| 40 | +0.000000 1000000.000000 8 4 |
| 41 | +0.000000 781157.000000 9 6 |
| 42 | +0.000000 781157.000000 9 7 |
| 43 | +0.000000 505438.000000 10 8 |
| 44 | +0.000000 505438.000000 10 9 |
| 45 | +505438.000000 549484.000000 11 8 |
| 46 | +505438.000000 549484.000000 11 9 |
| 47 | +781157.000000 1000000.000000 12 6 |
| 48 | +781157.000000 1000000.000000 12 7 |
| 49 | +549484.000000 1000000.000000 13 8 |
| 50 | +549484.000000 781157.000000 13 9 |
| 51 | +781157.000000 1000000.000000 13 12 |
| 52 | +""" |
| 53 | + |
| 54 | +toy_ts_sites_text = """\ |
| 55 | +position ancestral_state metadata |
| 56 | +200000.000000 A |
| 57 | +300000.000000 C |
| 58 | +520000.000000 G |
| 59 | +600000.000000 T |
| 60 | +900000.000000 A |
| 61 | +""" |
| 62 | + |
| 63 | +toy_ts_mutations_text = """\ |
| 64 | +site node time derived_state parent metadata |
| 65 | +0 9 unknown G -1 |
| 66 | +1 8 unknown A -1 |
| 67 | +2 9 unknown T -1 |
| 68 | +3 9 unknown C -1 |
| 69 | +4 12 unknown C -1 |
| 70 | +""" |
| 71 | + |
| 72 | +toy_ts_individuals_text = """\ |
| 73 | +flags |
| 74 | +0 |
| 75 | +0 |
| 76 | +0 |
| 77 | +""" |
| 78 | + |
| 79 | +toy_query_haplotypes_01 = np.array( |
| 80 | + [ |
| 81 | + [ |
| 82 | + 1, |
| 83 | + 0, |
| 84 | + -1, |
| 85 | + 0, |
| 86 | + 0, |
| 87 | + ], |
| 88 | + [ |
| 89 | + 0, |
| 90 | + 1, |
| 91 | + -1, |
| 92 | + 1, |
| 93 | + 0, |
| 94 | + ], |
| 95 | + ], |
| 96 | + dtype=np.int32, |
| 97 | +) |
| 98 | + |
| 99 | +toy_query_haplotypes_ACGT = np.array( |
| 100 | + [ |
| 101 | + [2, 1, -1, 3, 0], # GCTA |
| 102 | + [0, 0, -1, 1, 0], # AACA |
| 103 | + ], |
| 104 | + dtype=np.int32, |
| 105 | +) |
| 106 | + |
| 107 | + |
| 108 | +def get_toy_data(): |
| 109 | + ref_ts = tskit.load_text( |
| 110 | + nodes=io.StringIO(toy_ts_nodes_text), |
| 111 | + edges=io.StringIO(toy_ts_edges_text), |
| 112 | + sites=io.StringIO(toy_ts_sites_text), |
| 113 | + mutations=io.StringIO(toy_ts_mutations_text), |
| 114 | + individuals=io.StringIO(toy_ts_individuals_text), |
| 115 | + strict=False, |
| 116 | + ) |
| 117 | + query_h = toy_query_haplotypes_ACGT |
| 118 | + return [ref_ts, query_h] |
| 119 | + |
| 120 | + |
| 121 | +def get_tskit_forward_backward_matrices(ts, h): |
| 122 | + m = ts.num_sites |
| 123 | + fm = _tskit.CompressedMatrix(ts._ll_tree_sequence) |
| 124 | + bm = _tskit.CompressedMatrix(ts._ll_tree_sequence) |
| 125 | + ls_hmm = _tskit.LsHmm( |
| 126 | + ts._ll_tree_sequence, np.zeros(m) + 0.1, np.zeros(m) + 0.1, acgt_alleles=True |
| 127 | + ) |
| 128 | + ls_hmm.forward_matrix(h, fm) |
| 129 | + ls_hmm.backward_matrix(h, fm.normalisation_factor, bm) |
| 130 | + return [fm.decode(), bm.decode()] |
| 131 | + |
| 132 | + |
| 133 | +# BEAGLE 4.1 was run on the toy data set above using default parameters. |
| 134 | +# |
| 135 | +# In the query VCF, the site at position 520,000 was redacted and then imputed. |
| 136 | +# Note that the ancestral allele in the simulated tree sequence is |
| 137 | +# treated as the REF in the VCFs. |
| 138 | +# |
| 139 | +# The following are the forward probability matrices and backward probability |
| 140 | +# matrices calculated when imputing into the third individual above. There are |
| 141 | +# two sets of matrices, one for each haplotype. |
| 142 | +# |
| 143 | +# Notes about calculations: |
| 144 | +# n = number of haplotypes in ref. panel |
| 145 | +# M = number of markers |
| 146 | +# m = index of marker (site) |
| 147 | +# h = index of haplotype in ref. panel |
| 148 | +# |
| 149 | +# In forward probability matrix, |
| 150 | +# fwd[m][h] = emission prob., if m = 0 (first marker) |
| 151 | +# fwd[m][h] = emission prob. * (scale * fwd[m - 1][h] + shift), otherwise |
| 152 | +# where scale = (1 - switch prob.)/sum of fwd[m - 1], |
| 153 | +# and shift = switch prob./n. |
| 154 | +# |
| 155 | +# In backward probability matrix, |
| 156 | +# bwd[m][h] = 1, if m = M - 1 (last marker) // DON'T SEE THIS IN BEAGLE |
| 157 | +# unadj. bwd[m][h] = emission prob. / n |
| 158 | +# bwd[m][h] = (unadj. bwd[m][h] + shift) * scale, otherwise |
| 159 | +# where scale = (1 - switch prob.)/sum of unadj. bwd[m], |
| 160 | +# and shift = switch prob./n. |
| 161 | +# |
| 162 | +# For each site, the sum of backward value over all haplotypes is calculated |
| 163 | +# before scaling and shifting. |
| 164 | + |
| 165 | +beagle_fwd_matrix_text_1 = """ |
| 166 | +m,h,probRec,probNoRec,noErrProb,errProb,refAl,queryAl,shiftFac,scaleFac,sumSite,val, |
| 167 | +0,0,0.000000,1.000000,0.999900,0.000100,1,1,0.000000,1.000000,0.999900,0.999900, |
| 168 | +0,1,0.000000,1.000000,0.999900,0.000100,0,1,0.000000,1.000000,1.000000,0.000100, |
| 169 | +0,2,0.000000,1.000000,0.999900,0.000100,1,1,0.000000,1.000000,1.999900,0.999900, |
| 170 | +0,3,0.000000,1.000000,0.999900,0.000100,1,1,0.000000,1.000000,2.999800,0.999900, |
| 171 | +0,4,0.000000,1.000000,0.999900,0.000100,0,1,0.000000,1.000000,2.999900,0.000100, |
| 172 | +0,5,0.000000,1.000000,0.999900,0.000100,1,1,0.000000,1.000000,3.999800,0.999900, |
| 173 | +1,0,1.000000,0.000000,0.999900,0.000100,0,0,0.166667,0.000000,0.166650,0.166650, |
| 174 | +1,1,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.166667,0.000017, |
| 175 | +1,2,1.000000,0.000000,0.999900,0.000100,0,0,0.166667,0.000000,0.333317,0.166650, |
| 176 | +1,3,1.000000,0.000000,0.999900,0.000100,0,0,0.166667,0.000000,0.499967,0.166650, |
| 177 | +1,4,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.499983,0.000017, |
| 178 | +1,5,1.000000,0.000000,0.999900,0.000100,0,0,0.166667,0.000000,0.666633,0.166650, |
| 179 | +2,0,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.000017,0.000017, |
| 180 | +2,1,1.000000,0.000000,0.999900,0.000100,0,0,0.166667,0.000000,0.166667,0.166650, |
| 181 | +2,2,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.166683,0.000017, |
| 182 | +2,3,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.166700,0.000017, |
| 183 | +2,4,1.000000,0.000000,0.999900,0.000100,0,0,0.166667,0.000000,0.333350,0.166650, |
| 184 | +2,5,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.333367,0.000017, |
| 185 | +3,0,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.000017,0.000017, |
| 186 | +3,1,1.000000,0.000000,0.999900,0.000100,0,0,0.166667,0.000000,0.166667,0.166650, |
| 187 | +3,2,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.166683,0.000017, |
| 188 | +3,3,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.166700,0.000017, |
| 189 | +3,4,1.000000,0.000000,0.999900,0.000100,0,0,0.166667,0.000000,0.333350,0.166650, |
| 190 | +3,5,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.333367,0.000017, |
| 191 | +""" |
| 192 | + |
| 193 | +beagle_bwd_matrix_text_1 = """ |
| 194 | +m,h,probRec,probNoRec,noErrProb,errProb,refAl,queryAl,shiftFac,scaleFac,sumSite,val, |
| 195 | +3,0,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 196 | +3,1,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 197 | +3,2,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 198 | +3,3,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 199 | +3,4,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 200 | +3,5,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 201 | +2,0,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.333367,0.166667, |
| 202 | +2,1,1.000000,0.000000,0.999900,0.000100,0,0,0.000000,0.166667,0.333367,0.166667, |
| 203 | +2,2,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.333367,0.166667, |
| 204 | +2,3,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.333367,0.166667, |
| 205 | +2,4,1.000000,0.000000,0.999900,0.000100,0,0,0.000000,0.166667,0.333367,0.166667, |
| 206 | +2,5,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.333367,0.166667, |
| 207 | +1,0,1.000000,0.000000,0.999900,0.000100,0,0,0.000000,0.166667,0.333367,0.166667, |
| 208 | +1,1,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.333367,0.166667, |
| 209 | +1,2,1.000000,0.000000,0.999900,0.000100,0,0,0.000000,0.166667,0.333367,0.166667, |
| 210 | +1,3,1.000000,0.000000,0.999900,0.000100,0,0,0.000000,0.166667,0.333367,0.166667, |
| 211 | +1,4,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.333367,0.166667, |
| 212 | +1,5,1.000000,0.000000,0.999900,0.000100,0,0,0.000000,0.166667,0.333367,0.166667, |
| 213 | +0,0,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.666633,0.166667, |
| 214 | +0,1,1.000000,0.000000,0.999900,0.000100,0,0,0.000000,0.166667,0.666633,0.166667, |
| 215 | +0,2,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.666633,0.166667, |
| 216 | +0,3,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.666633,0.166667, |
| 217 | +0,4,1.000000,0.000000,0.999900,0.000100,0,0,0.000000,0.166667,0.666633,0.166667, |
| 218 | +0,5,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.666633,0.166667, |
| 219 | +""" |
| 220 | + |
| 221 | +beagle_fwd_matrix_text_2 = """ |
| 222 | +m,h,probRec,probNoRec,noErrProb,errProb,refAl,queryAl,shiftFac,scaleFac,sumSite,val, |
| 223 | +0,0,0.000000,1.000000,0.999900,0.000100,1,0,0.000000,1.000000,0.000100,0.000100, |
| 224 | +0,1,0.000000,1.000000,0.999900,0.000100,0,0,0.000000,1.000000,1.000000,0.999900, |
| 225 | +0,2,0.000000,1.000000,0.999900,0.000100,1,0,0.000000,1.000000,1.000100,0.000100, |
| 226 | +0,3,0.000000,1.000000,0.999900,0.000100,1,0,0.000000,1.000000,1.000200,0.000100, |
| 227 | +0,4,0.000000,1.000000,0.999900,0.000100,0,0,0.000000,1.000000,2.000100,0.999900, |
| 228 | +0,5,0.000000,1.000000,0.999900,0.000100,1,0,0.000000,1.000000,2.000200,0.000100, |
| 229 | +1,0,1.000000,0.000000,0.999900,0.000100,0,1,0.166667,0.000000,0.000017,0.000017, |
| 230 | +1,1,1.000000,0.000000,0.999900,0.000100,1,1,0.166667,0.000000,0.166667,0.166650, |
| 231 | +1,2,1.000000,0.000000,0.999900,0.000100,0,1,0.166667,0.000000,0.166683,0.000017, |
| 232 | +1,3,1.000000,0.000000,0.999900,0.000100,0,1,0.166667,0.000000,0.166700,0.000017, |
| 233 | +1,4,1.000000,0.000000,0.999900,0.000100,1,1,0.166667,0.000000,0.333350,0.166650, |
| 234 | +1,5,1.000000,0.000000,0.999900,0.000100,0,1,0.166667,0.000000,0.333367,0.000017, |
| 235 | +2,0,1.000000,0.000000,0.999900,0.000100,1,1,0.166667,0.000000,0.166650,0.166650, |
| 236 | +2,1,1.000000,0.000000,0.999900,0.000100,0,1,0.166667,0.000000,0.166667,0.000017, |
| 237 | +2,2,1.000000,0.000000,0.999900,0.000100,1,1,0.166667,0.000000,0.333317,0.166650, |
| 238 | +2,3,1.000000,0.000000,0.999900,0.000100,1,1,0.166667,0.000000,0.499967,0.166650, |
| 239 | +2,4,1.000000,0.000000,0.999900,0.000100,0,1,0.166667,0.000000,0.499983,0.000017, |
| 240 | +2,5,1.000000,0.000000,0.999900,0.000100,1,1,0.166667,0.000000,0.666633,0.166650, |
| 241 | +3,0,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.000017,0.000017, |
| 242 | +3,1,1.000000,0.000000,0.999900,0.000100,0,0,0.166667,0.000000,0.166667,0.166650, |
| 243 | +3,2,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.166683,0.000017, |
| 244 | +3,3,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.166700,0.000017, |
| 245 | +3,4,1.000000,0.000000,0.999900,0.000100,0,0,0.166667,0.000000,0.333350,0.166650, |
| 246 | +3,5,1.000000,0.000000,0.999900,0.000100,1,0,0.166667,0.000000,0.333367,0.000017, |
| 247 | +""" |
| 248 | + |
| 249 | +beagle_bwd_matrix_text_2 = """ |
| 250 | +m,h,probRec,probNoRec,noErrProb,errProb,refAl,queryAl,shiftFac,scaleFac,sumSite,val, |
| 251 | +3,0,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 252 | +3,1,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 253 | +3,2,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 254 | +3,3,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 255 | +3,4,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 256 | +3,5,-1,-1,-1,-1,-1,-1,-1,-1,-1,1.000000, |
| 257 | +2,0,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.333367,0.166667, |
| 258 | +2,1,1.000000,0.000000,0.999900,0.000100,0,0,0.000000,0.166667,0.333367,0.166667, |
| 259 | +2,2,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.333367,0.166667, |
| 260 | +2,3,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.333367,0.166667, |
| 261 | +2,4,1.000000,0.000000,0.999900,0.000100,0,0,0.000000,0.166667,0.333367,0.166667, |
| 262 | +2,5,1.000000,0.000000,0.999900,0.000100,1,0,0.000000,0.166667,0.333367,0.166667, |
| 263 | +1,0,1.000000,0.000000,0.999900,0.000100,0,1,0.000000,0.166667,0.666633,0.166667, |
| 264 | +1,1,1.000000,0.000000,0.999900,0.000100,1,1,0.000000,0.166667,0.666633,0.166667, |
| 265 | +1,2,1.000000,0.000000,0.999900,0.000100,0,1,0.000000,0.166667,0.666633,0.166667, |
| 266 | +1,3,1.000000,0.000000,0.999900,0.000100,0,1,0.000000,0.166667,0.666633,0.166667, |
| 267 | +1,4,1.000000,0.000000,0.999900,0.000100,1,1,0.000000,0.166667,0.666633,0.166667, |
| 268 | +1,5,1.000000,0.000000,0.999900,0.000100,0,1,0.000000,0.166667,0.666633,0.166667, |
| 269 | +0,0,1.000000,0.000000,0.999900,0.000100,1,1,0.000000,0.166667,0.333367,0.166667, |
| 270 | +0,1,1.000000,0.000000,0.999900,0.000100,0,1,0.000000,0.166667,0.333367,0.166667, |
| 271 | +0,2,1.000000,0.000000,0.999900,0.000100,1,1,0.000000,0.166667,0.333367,0.166667, |
| 272 | +0,3,1.000000,0.000000,0.999900,0.000100,1,1,0.000000,0.166667,0.333367,0.166667, |
| 273 | +0,4,1.000000,0.000000,0.999900,0.000100,0,1,0.000000,0.166667,0.333367,0.166667, |
| 274 | +0,5,1.000000,0.000000,0.999900,0.000100,1,1,0.000000,0.166667,0.333367,0.166667, |
| 275 | +""" |
| 276 | + |
| 277 | + |
| 278 | +def parse_matrix(csv_text): |
| 279 | + # This returns a record array, which is essentially the same as a |
| 280 | + # pandas dataframe, which we can access via df["m"] etc. |
| 281 | + return np.lib.npyio.recfromcsv(io.StringIO(csv_text)) |
| 282 | + |
| 283 | + |
| 284 | +def test_toy_example(): |
| 285 | + ref_ts, query = get_toy_data() |
| 286 | + print(list(ref_ts.haplotypes())) |
| 287 | + print(ref_ts) |
| 288 | + print(query) |
| 289 | + tskit_fwd, tskit_bwd = get_tskit_forward_backward_matrices(ref_ts, query[0]) |
| 290 | + beagle_fwd = parse_matrix(beagle_fwd_matrix_text_1) |
| 291 | + beagle_bwd = parse_matrix(beagle_bwd_matrix_text_1) |
| 292 | + print("Forward probability matrix") |
| 293 | + print("tskit") |
| 294 | + print(tskit_fwd) |
| 295 | + print("beagle") |
| 296 | + print(beagle_fwd["val"].reshape((4, 6))) |
| 297 | + print("Backward probability matrix") |
| 298 | + print("tskit") |
| 299 | + print(tskit_bwd) |
| 300 | + print("beagle") |
| 301 | + print(beagle_bwd["val"].reshape((4, 6))) |
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