|
| 1 | +# Make sure current directory is in path. |
| 2 | +# That's not true while doctesting (sage -t). |
| 3 | +if '' not in sys.path: |
| 4 | + sys.path = [''] + sys.path |
| 5 | + |
| 6 | +from igp import * |
| 7 | + |
| 8 | +########################################## |
| 9 | +# MIP approach to search for 2q example |
| 10 | +# use code in kslope_mip.sage |
| 11 | +########################################## |
| 12 | + |
| 13 | +def print_trivial_additive_points_2q(filename, q, f, a): |
| 14 | + """ |
| 15 | + EXAMPLES:: |
| 16 | +
|
| 17 | + sage: print_trivial_additive_points_2q(sys.stdout, 3, 2/3, 1/3) |
| 18 | + p_0_0 = 0 |
| 19 | + p_0_1 = 0 |
| 20 | + p_0_2 = 0 |
| 21 | + p_0_3 = 0 |
| 22 | + p_1_3 = 0 |
| 23 | + p_2_3 = 0 |
| 24 | + p_3_3 = 0 |
| 25 | + p_0_2 = 0 |
| 26 | + p_1_1 = 0 |
| 27 | + p_2_0 = 0 |
| 28 | + p_2_3 = 0 |
| 29 | + p_3_2 = 0 |
| 30 | + p_1_0 = 0 |
| 31 | + p_1_1 = 0 |
| 32 | + """ |
| 33 | + bkpt = [x/q for x in range(q+1)] |
| 34 | + # border x = 0 and border y = 0 are green |
| 35 | + for x in bkpt: |
| 36 | + print >> filename, '%s = 0' % vertex_variable(q, (0, x)) |
| 37 | + for x in bkpt[1::]: |
| 38 | + print >> filename, '%s = 0' % vertex_variable(q, (x, 1)) |
| 39 | + # diagonals corresponding to f |
| 40 | + for x in bkpt: |
| 41 | + if x < f: |
| 42 | + print >> filename, '%s = 0' % vertex_variable(q, (x, f - x)) |
| 43 | + elif x == f: |
| 44 | + print >> filename, '%s = 0' % vertex_variable(q, (x, f - x)) |
| 45 | + print >> filename, '%s = 0' % vertex_variable(q, (x, f - x + 1)) |
| 46 | + elif x > f: |
| 47 | + print >> filename, '%s = 0' % vertex_variable(q, (x, f - x + 1)) |
| 48 | + |
| 49 | + b = f - a |
| 50 | + print >> filename, '%s = 0' % vertex_variable(q, (b - a + 1/q, a - 1/q)) |
| 51 | + print >> filename, '%s = 0' % vertex_variable(q, (b - a + 1/q, a)) |
| 52 | + |
| 53 | +def write_lpfile_2q(q, f, a, kslopes, maxstep=None, m=0): |
| 54 | + """ |
| 55 | + EXAMPLES: |
| 56 | +
|
| 57 | + sage: write_lpfile_2q(37, 25/37, 11/37, 4, maxstep=2, m=4) # not tested |
| 58 | + """ |
| 59 | + if maxstep is None: |
| 60 | + maxstep = q |
| 61 | + |
| 62 | + destdir = output_dir+"2q_mip/" |
| 63 | + mkdir_p(destdir) |
| 64 | + filename = open(destdir + "mip_q%s_f%s_a%s_%sslope_%smaxstep_m%s.lp" % (q, int(f*q), int(a*q), kslopes, maxstep, m), "w") |
| 65 | + faces_2d = [] |
| 66 | + faces_diag = [] |
| 67 | + faces_hor = [] |
| 68 | + faces_ver = [] |
| 69 | + faces_0d = [] |
| 70 | + for xx in range(q): |
| 71 | + for yy in range(q): |
| 72 | + faces_2d.append( Face(([xx/q, (xx+1)/q], [yy/q, (yy+1)/q], [(xx+yy)/q, (xx+yy+1)/q])) ) |
| 73 | + faces_2d.append( Face(([xx/q, (xx+1)/q], [yy/q, (yy+1)/q], [(xx+yy+1)/q, (xx+yy+2)/q])) ) |
| 74 | + faces_diag.append( Face(([xx/q, (xx+1)/q], [yy/q, (yy+1)/q], [(xx+yy+1)/q])) ) |
| 75 | + |
| 76 | + for xx in range(q): |
| 77 | + for yy in range(q+1): |
| 78 | + faces_hor.append( Face(([xx/q, (xx+1)/q], [yy/q], [(xx+yy)/q, (xx+yy+1)/q])) ) |
| 79 | + faces_ver.append( Face(([yy/q], [xx/q, (xx+1)/q], [(xx+yy)/q, (xx+yy+1)/q])) ) |
| 80 | + |
| 81 | + for xx in range(q+1): |
| 82 | + for yy in range(q+1): |
| 83 | + faces_0d.append( Face(([xx/q], [yy/q], [(xx+yy)/q])) ) |
| 84 | + |
| 85 | + print >> filename, '\ MIP model with q = %s, f = %s, a = %s, num of slopes = %s, maxstep of tran/refl = %s, small_m = %s' % (q, f, a, kslopes, maxstep, m) |
| 86 | + |
| 87 | + print >> filename, 'Maximize' |
| 88 | + #print >> filename, 0 |
| 89 | + print_obj_max_slope_slack(filename, kslopes) |
| 90 | + #print_obj_max_subadd_slack(filename, q) # is a constant! |
| 91 | + #print_obj_min_directly_covered_times(filename, q) |
| 92 | + #print_obj_min_undirectly_covered_times(filename, q) |
| 93 | + #print_obj_min_covered_times_max_subadd_slack(filename, q, maxstep=maxstep) |
| 94 | + #print_obj_5slope22(filename, q, weight=1) |
| 95 | + #print_obj_min_add_points(filename, q, weight=1) |
| 96 | + print >> filename |
| 97 | + |
| 98 | + print >> filename, 'Subject to' |
| 99 | + for face in faces_2d + faces_diag + faces_hor + faces_ver: |
| 100 | + #if face.minimal_triple[0][0] <= face.minimal_triple[1][0]: |
| 101 | + print_logical_constraints(filename, q, face) |
| 102 | + |
| 103 | + for face in faces_0d: |
| 104 | + if face.minimal_triple[0][0] < face.minimal_triple[1][0]: |
| 105 | + print_xy_swapped_constraints(filename, q, face) |
| 106 | + |
| 107 | + # if no 1/m trick for subadditivity, set m=0 in print_fn_minimality_test. |
| 108 | + print_fn_minimality_test(filename, q, f, m) |
| 109 | + |
| 110 | + print_trivial_additive_points_2q(filename, q, f, a) |
| 111 | + |
| 112 | + for zz in range(q): |
| 113 | + for xx in range(q): |
| 114 | + x = xx / q |
| 115 | + z = zz / q |
| 116 | + if x != z: |
| 117 | + if maxstep > 1: |
| 118 | + print_move_constraints(filename, q, x, z) |
| 119 | + for step in range(1, maxstep): |
| 120 | + print_translation_i_constraints(filename, q, x, z, step) |
| 121 | + print_reflection_i_constraints(filename, q, x, z, step) |
| 122 | + |
| 123 | + for zz in range(q): |
| 124 | + z = zz / q |
| 125 | + print_directly_covered_constraints(filename, q, z) |
| 126 | + for step in range(1, maxstep): |
| 127 | + print_undirectly_covered_i_constraints(filename, q, z, step) |
| 128 | + |
| 129 | + for zz in range(q): |
| 130 | + z = zz / q |
| 131 | + if z != a - 1/q and z != f - a: |
| 132 | + print >> filename, '%s = 0' % covered_i_variable(q, z, maxstep - 1) |
| 133 | + else: |
| 134 | + print >> filename, '%s = 1' % covered_i_variable(q, z, maxstep - 1) |
| 135 | + |
| 136 | + print_slope_constraints_2q(filename, q, f, a, kslopes, m) |
| 137 | + |
| 138 | + print >> filename, 'Bounds' |
| 139 | + print_fn_bounds(filename, q) |
| 140 | + print_slope_bounds(filename, q, kslopes) |
| 141 | + |
| 142 | + print >> filename, 'Binary' |
| 143 | + for face in faces_2d + faces_diag + faces_hor + faces_ver + faces_0d : |
| 144 | + print >> filename, face_variable(q, face), |
| 145 | + |
| 146 | + for z in range(q): |
| 147 | + for step in range(maxstep): |
| 148 | + print >> filename, 'c_%s_%s' % (z, step), |
| 149 | + for z in range(q): |
| 150 | + for x in range(q): |
| 151 | + if x != z: |
| 152 | + if maxstep > 1: |
| 153 | + print >> filename, 'm_%s_%s' % (x, z), |
| 154 | + for step in range(1, maxstep): |
| 155 | + print >> filename, 't_%s_%s_%s' % (x, z, step), |
| 156 | + print >> filename, 'r_%s_%s_%s' % (x, z, step), |
| 157 | + |
| 158 | + for k in range(kslopes): |
| 159 | + for j in range(q): |
| 160 | + print >> filename, '%s' % interval_slope_variable(j, k), |
| 161 | + |
| 162 | + print >> filename |
| 163 | + print >> filename, 'End' |
| 164 | + filename.close() |
| 165 | + |
| 166 | +def print_slope_constraints_2q(filename, q, f, a, kslopes, m=0): |
| 167 | + """ |
| 168 | + EXAMPLES:: |
| 169 | +
|
| 170 | + sage: print_slope_constraints_2q(sys.stdout, 4, 3/4, 2/4, 3, m=0) |
| 171 | + s_0 - s_1 >= 0 |
| 172 | + s_1 - s_2 >= 0 |
| 173 | + s_0 - 4 fn_1 = 0 |
| 174 | + i_0_s_0 = 1 |
| 175 | + s_2 + 4 fn_3 = 0 |
| 176 | + i_3_s_2 = 1 |
| 177 | + s_0 + 4 fn_1 - 4 fn_2 + 8 i_1_s_0 <= 8 |
| 178 | + s_0 + 4 fn_1 - 4 fn_2 - 8 i_1_s_0 >= -8 |
| 179 | + s_1 + 4 fn_1 - 4 fn_2 + 8 i_1_s_1 <= 8 |
| 180 | + s_1 + 4 fn_1 - 4 fn_2 - 8 i_1_s_1 >= -8 |
| 181 | + s_2 + 4 fn_1 - 4 fn_2 + 8 i_1_s_2 <= 8 |
| 182 | + s_2 + 4 fn_1 - 4 fn_2 - 8 i_1_s_2 >= -8 |
| 183 | + s_0 + 4 fn_2 - 4 fn_3 + 8 i_2_s_0 <= 8 |
| 184 | + s_0 + 4 fn_2 - 4 fn_3 - 8 i_2_s_0 >= -8 |
| 185 | + s_1 + 4 fn_2 - 4 fn_3 + 8 i_2_s_1 <= 8 |
| 186 | + s_1 + 4 fn_2 - 4 fn_3 - 8 i_2_s_1 >= -8 |
| 187 | + s_2 + 4 fn_2 - 4 fn_3 + 8 i_2_s_2 <= 8 |
| 188 | + s_2 + 4 fn_2 - 4 fn_3 - 8 i_2_s_2 >= -8 |
| 189 | + + i_0_s_0 + i_0_s_1 + i_0_s_2 = 1 |
| 190 | + + i_1_s_0 + i_1_s_1 + i_1_s_2 = 1 |
| 191 | + + i_2_s_0 + i_2_s_1 + i_2_s_2 = 1 |
| 192 | + + i_3_s_0 + i_3_s_1 + i_3_s_2 = 1 |
| 193 | + + i_0_s_0 + i_1_s_0 + i_2_s_0 + i_3_s_0 >= 1 |
| 194 | + + i_0_s_1 + i_1_s_1 + i_2_s_1 + i_3_s_1 >= 1 |
| 195 | + + i_0_s_2 + i_1_s_2 + i_2_s_2 + i_3_s_2 >= 1 |
| 196 | + i_1_s_0 + i_0_s_0 <= 1 |
| 197 | + i_1_s_0 - i_1_s_0 = 0 |
| 198 | + i_1_s_0 + i_2_s_0 <= 1 |
| 199 | + i_1_s_0 + i_3_s_0 <= 1 |
| 200 | + i_1_s_1 + i_0_s_1 <= 1 |
| 201 | + i_1_s_1 - i_1_s_1 = 0 |
| 202 | + i_1_s_1 + i_2_s_1 <= 1 |
| 203 | + i_1_s_1 + i_3_s_1 <= 1 |
| 204 | + i_1_s_2 + i_0_s_2 <= 1 |
| 205 | + i_1_s_2 - i_1_s_2 = 0 |
| 206 | + i_1_s_2 + i_2_s_2 <= 1 |
| 207 | + i_1_s_2 + i_3_s_2 <= 1 |
| 208 | + """ |
| 209 | + # s_0 > s_1 > ... > s_kslopes-1 |
| 210 | + for k in range(0, kslopes - 1): |
| 211 | + if m == 0: |
| 212 | + print >> filename, '%s - %s >= 0' % (slope_variable(k), slope_variable(k+1)) |
| 213 | + else: |
| 214 | + print >> filename, '%s - %s >= %s' % (slope_variable(k), slope_variable(k+1), RR(q/m)) |
| 215 | + |
| 216 | + # first interval has the largest positive slope s_0 |
| 217 | + print >> filename, 's_0 - %s fn_1 = 0' % q |
| 218 | + print >> filename, 'i_0_s_0 = 1' |
| 219 | + # last interval has slope s_kslopes-1 |
| 220 | + print >> filename, 's_%s + %s fn_%s = 0' % (kslopes - 1, q, q - 1) |
| 221 | + print >> filename, 'i_%s_s_%s = 1' % (q - 1, kslopes - 1) |
| 222 | + # Condition: s_k + q(fn_j - fn_(j+1)) = 0 iff i_j_s_k = 1 |
| 223 | + # ==> 1) s_k + q * fn_j - q * fn_(j+1) <= 2*q * (1 - i_j_s_k) |
| 224 | + # ==> 2) s_k + q * fn_j - q * fn_(j+1) >= - 2*q * (1 - i_j_s_k) |
| 225 | + # ==> 3) sum i_j_s_k over k = 1 |
| 226 | + for j in range(1, q-1): |
| 227 | + for k in range(kslopes): |
| 228 | + print >> filename, 's_%s + %s fn_%s - %s fn_%s + %s %s <= %s' % (k, q, j, q, j + 1, 2*q, interval_slope_variable(j, k), 2*q) |
| 229 | + print >> filename, 's_%s + %s fn_%s - %s fn_%s - %s %s >= %s' % (k, q, j, q, j + 1, 2*q, interval_slope_variable(j, k), -2*q) |
| 230 | + for j in range(q): |
| 231 | + for k in range(kslopes): |
| 232 | + print >> filename, '+ %s' % interval_slope_variable(j, k), |
| 233 | + print >> filename, '= 1' |
| 234 | + # Condition: sum i_j_s_k over j >= 1 |
| 235 | + for k in range(kslopes): |
| 236 | + for j in range(q): |
| 237 | + print >> filename, '+ %s' % interval_slope_variable(j, k), |
| 238 | + print >> filename, '>= 1' |
| 239 | + # Two special intervals have the same slope value, |
| 240 | + # which is different from the slope values of other intervals |
| 241 | + ja = int(a * q) - 1 |
| 242 | + jb = int((f - a) * q) |
| 243 | + for k in range(kslopes): |
| 244 | + for j in range(q): |
| 245 | + if j == jb: |
| 246 | + print >> filename, '%s - %s = 0' % ( interval_slope_variable(ja, k), \ |
| 247 | + interval_slope_variable(jb, k) ) |
| 248 | + elif j != ja: |
| 249 | + print >> filename, '%s + %s <= 1' % ( interval_slope_variable(ja, k), \ |
| 250 | + interval_slope_variable(j, k) ) |
| 251 | + |
| 252 | +def refind_function_from_lpsolution_2q(filename, q, f, a): |
| 253 | + """ |
| 254 | + EXAMPLES:: |
| 255 | +
|
| 256 | + sage: h = refind_function_from_lpsolution_2q('solution_2q_example_m4.sol', 37, 25/37, 11/37) # not tested |
| 257 | + """ |
| 258 | + faces, fn = painted_faces_and_funciton_from_solution(filename, q) |
| 259 | + covered_intervals = generate_covered_intervals_from_faces(faces) |
| 260 | + additive_vertices = generate_additive_vertices_from_faces(q, faces) |
| 261 | + final_uncovered = [[a - 1/q, a], [f - a, f - a + 1 / q]] |
| 262 | + components = covered_intervals + [final_uncovered] |
| 263 | + fn_sym = generate_symbolic_continuous(None, components, field=QQ) |
| 264 | + ff = int(f * q) |
| 265 | + for h in generate_vertex_function(q, ff, fn_sym, additive_vertices): |
| 266 | + if not extremality_test(h): # h is not extreme |
| 267 | + logging.info("Testing the extremality of pi restricted to 1/2q.") |
| 268 | + h_2q = restrict_to_finite_group(h, f=f, oversampling=2, order=None) |
| 269 | + if extremality_test(h_2q): # but h restricted to 1/2q is extreme |
| 270 | + logging.info("Find a valid 2q_example!") |
| 271 | + return h |
| 272 | +# Comments: |
| 273 | +# def kzh_2q_example_1() is obtained by |
| 274 | +# LP model: mip_q37_f25_a11_4slope_2maxstep_m4.lp |
| 275 | +# q = 37; f = 25/37; a = 11/37; |
| 276 | +# given number of slopes = 4; maxstep = 2; |
| 277 | +# slope gap >= q/4; subadditivity slack = 1/4; |
| 278 | +# obj = max_slope_slack. |
| 279 | +# |
| 280 | +# Gurobi run on my laptop (276s, obj = 33.66393) |
| 281 | +# Optimal solution: solution_2q_example_m4.sol |
| 282 | +# |
| 283 | +# ( Or |
| 284 | +# (1) LP model: mip_q37_f25_a11_4slope_2maxstep_m12.lp |
| 285 | +# slope gap >= q/12; subadditivity slack = 1/12; |
| 286 | +# Gurobi run on my laptop (1080s, obj = 33.66393) |
| 287 | +# Optimal solution: solution_2q_example_m12.sol |
| 288 | +# |
| 289 | +# (2) LP model: mip_q37_f25_a11_4slope_2maxstep_m12slopegaponly.lp |
| 290 | +# slope gap >= q/12; no 1/m trick on subadditivity slack; |
| 291 | +# Gurobi run on point.math.ucdavis.edu (7412s, obj = 33.66393) |
| 292 | +# Optimal solution: solution_2q_example_m12slopegaponly.sol ) |
| 293 | +# |
| 294 | +# The vertex function is a 4-slope non-extreme function, |
| 295 | +# whose restriction to 1/2q is extreme. |
| 296 | +# |
| 297 | +# This two_q_example is obtained by: |
| 298 | +# sage: h = refind_function_from_lpsolution_2q('solution_2q_example_m4.sol', 37, 25/37, 11/37) # not tested |
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