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`nx_ice_distribution_test.nx` source

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1// nx_ice_distribution_test.nx -- gate for the derived geometric coupling.
2//
3// THE CLAIM UNDER TEST is that nx_ice_recrystal's asserted coupling was not
4// merely unproven but WRONG IN A KNOWN DIRECTION, and that the right value
5// falls out of a size distribution as exact arithmetic.
6//
7// T4 is the measurement that matters: the number fraction of crystals lost
8// is far larger than the mass fraction melted, so a coupling of 1.0 -- which
9// is the claim that they are equal -- under-states how fast the mean size
10// grows.  T5 puts a number on how wrong, and T6 states the direction as a
11// verdict rather than leaving a reader to work it out.
12//
13// T2 is the conservation law that keeps the rest honest: melting and
14// redepositing must not change total mass, and if it did, every growth
15// figure here would be an artefact of losing or inventing ice.
16// expect_exit: 0   license_tier: ORIGINAL
17import "nx_syscalls.nx"
18import "nx_ice_distribution.nx"
19import "nx_ice_recrystal.nx"
20
21func tw(s: *u8) -> i64 { var n: i64 = 0; while s[n] != (0 as u8) { n = n + 1 } sys_write(1, s, n); return 0 }
22func tn(v: i64) -> i64 { let b: *u8 = sys_mmap(24); var m: i64 = v; if m < 0 { sys_write(1, "-" as *u8, 1); m = 0 - m } let t: *u8 = sys_mmap(24); var k: i64 = 0; if m == 0 { t[0] = 48 as u8; k = 1 } while m > 0 { t[k] = (48 + (m % 10)) as u8; m = m / 10; k = k + 1 } var i: i64 = 0; while i < k { b[i] = t[k - 1 - i]; i = i + 1 } sys_write(1, b, k); return 0 }
23func iabs(v: i64) -> i64 { if v < 0 { return 0 - v } return v }
24
25func main() -> i64 {
  var pass: i64 = 0
  var total: i64 = 0
28
  let s: *IceDist = dist_reference()
30
  // --- T1  The reference profile is well formed and ASCENDING, which is a
  //         precondition of the melt walk rather than a convention: melting
  //         the wrong end would silently invert every result below. ---
  total = total + 1
  var ok1: i64 = 1
  if dist_is_ascending(s) != 1 { ok1 = 0 }
  if dist_total_count(s) <= 0 { ok1 = 0 }
  if dist_total_mass(s) <= 0 { ok1 = 0 }
  let mean0: i64 = dist_mean_diameter(s)
  if mean0 < 150 { ok1 = 0 }
  if mean0 > 350 { ok1 = 0 }
  tw("T1 reference profile ascending, " as *u8); tn(dist_total_count(s))
  tw(" crystals, mean D=" as *u8); tn(mean0); tw(" (0.1um): " as *u8)
  if ok1 == 1 { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
45
  // --- T2  ***MASS CONSERVATION.***  Melting and redepositing moves ice
  //         between crystals; it must not create or destroy any.  Every
  //         growth number in this gate is meaningless if this fails. ---
  total = total + 1
  let s2: *IceDist = dist_reference()
  let m_before: i64 = dist_total_mass(s2)
  dist_apply_cycle(s2, 100)
  let m_after: i64 = dist_total_mass(s2)
  let drift: i64 = iabs(m_after - m_before) * 1000 / m_before
  tw("T2 mass before=" as *u8); tn(m_before); tw(" after a 100permil cycle=" as *u8); tn(m_after)
  // The tolerance is not a fudge: diameters are quantised to 0.1 um, so a
  // bin's volume carries up to 3 x 0.05/d relative error after rounding --
  // about 7 permil for a 20 um crystal, partly cancelling across bins.
  // Anything beyond that is a leak, not quantisation, and 175 permil is
  // what this check caught on the first run.
  tw(", drift=" as *u8); tn(drift); tw(" permil (quantisation budget 15): " as *u8)
  if drift <= 15 { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
63
  // --- T3  A cycle COARSENS: the mean diameter must rise, and the crystal
  //         count must fall.  Those are two independent consequences of the
  //         same mechanism, so checking both is not redundant. ---
  total = total + 1
  let mean_after: i64 = dist_mean_diameter(s2)
  let cnt_after: i64 = dist_total_count(s2)
  tw("T3 after one cycle: mean D " as *u8); tn(mean0); tw("->" as *u8); tn(mean_after)
  tw(", count " as *u8); tn(dist_total_count(s)); tw("->" as *u8); tn(cnt_after); tw(": " as *u8)
  var ok3: i64 = 1
  if mean_after <= mean0 { ok3 = 0 }
  if cnt_after >= dist_total_count(s) { ok3 = 0 }
  if ok3 == 1 { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
76
  // --- T4  ***THE MEASUREMENT THAT KILLS THE ASSERTION.***  Melting 100
  //         permil of the MASS removes far more than 100 permil of the
  //         COUNT, because small crystals are numerous and light.  A
  //         coupling of 1.0 is precisely the claim that these two numbers
  //         are equal. ---
  total = total + 1
  let phi: i64 = 100
  let nu: i64 = dist_number_fraction_permil(s, phi)
  tw("T4 melting " as *u8); tn(phi); tw(" permil of the MASS removes " as *u8); tn(nu)
  tw(" permil of the COUNT -- a coupling of 1.0 claims these are equal: " as *u8)
  var ok4: i64 = 1
  if nu <= phi { ok4 = 0 }
  if nu >= 1000 { ok4 = 0 }
  if ok4 == 1 { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
91
  // --- T5  ***HOW WRONG, AS A NUMBER.***  The derived coupling against the
  //         constant nx_ice_recrystal asserts. ---
  total = total + 1
  let derived: i64 = dist_derived_coupling(s, phi)
  let err: i64 = dist_coupling_error_permil(s, phi, IR_COUPLING)
  tw("T5 derived coupling=" as *u8); tn(derived)
  tw(" vs asserted IR_COUPLING=" as *u8); tn(IR_COUPLING)
  tw(" -> assertion is off by " as *u8); tn(err); tw(" permil: " as *u8)
  var ok5: i64 = 1
  if derived <= IR_COUPLING { ok5 = 0 }
  if err >= 0 { ok5 = 0 }
  if ok5 == 1 { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
104
  // --- T6  ***THE DIRECTION, AS A VERDICT.***  The asserted constant
  //         UNDER-states damage, which is the direction that reports a
  //         product as fine when it is not.  A consumer must not have to
  //         infer this from the sign of a number. ---
  total = total + 1
  let conservative: i64 = dist_asserted_is_conservative(s, phi, IR_COUPLING)
  tw("T6 is the asserted coupling conservative? " as *u8); tn(conservative)
  tw(" (0 = it UNDER-states damage, the unsafe direction): " as *u8)
  if conservative == 0 { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
114
  // --- T7  NON-VACUITY of T6: the verdict must be capable of saying yes.
  //         Handed a genuinely conservative constant it must report 1, so
  //         T6 is measuring the constant and not hard-wired to complain. ---
  total = total + 1
  let big: i64 = derived * 2
  let conservative2: i64 = dist_asserted_is_conservative(s, phi, big)
  tw("T7 handed a deliberately large coupling (" as *u8); tn(big)
  tw(") the same check reports conservative=" as *u8); tn(conservative2); tw(" (want 1): " as *u8)
  if conservative2 == 1 { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
124
  // --- T8  The coupling DEPENDS ON THE DISTRIBUTION, which is the whole
  //         reason it could never have been a universal constant.  A
  //         narrow, uniform population loses far less of its count for the
  //         same mass melted than a broad one with a small-crystal tail. ---
  total = total + 1
  let narrow: *IceDist = dist_new(3)
  dist_set(narrow, 0, 240, 1000)
  dist_set(narrow, 1, 250, 1000)
  dist_set(narrow, 2, 260, 1000)
  let c_narrow: i64 = dist_derived_coupling(narrow, phi)
  tw("T8 broad profile coupling=" as *u8); tn(derived)
  tw(" vs narrow profile coupling=" as *u8); tn(c_narrow)
  tw(" -- not a universal constant: " as *u8)
  var ok8: i64 = 1
  if c_narrow == DIST_INVALID { ok8 = 0 }
  if c_narrow >= derived { ok8 = 0 }
  if ok8 == 1 { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
142
  // --- T9  Zero melt is zero growth, exactly.  The control that proves the
  //         growth tracks the excursion rather than being applied to every
  //         distribution the model touches. ---
  total = total + 1
  let s9: *IceDist = dist_reference()
  let mean9: i64 = dist_mean_diameter(s9)
  dist_apply_cycle(s9, 0)
  var ok9: i64 = 1
  if dist_mean_diameter(s9) != mean9 { ok9 = 0 }
  if dist_number_fraction_permil(s, 0) != 0 { ok9 = 0 }
  if dist_volume_growth_permil(s, 0) != 0 { ok9 = 0 }
  tw("T9 a zero-amplitude cycle changes nothing at all: " as *u8)
  if ok9 == 1 { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
156
  // --- T10 FAIL-CLOSED, and the reference profile is FLAGGED.  A caller
  //         using the built-in shape rather than measured bin counts must
  //         be able to tell -- otherwise a shape-correct answer reads as a
  //         measured one. ---
  total = total + 1
  var ok10: i64 = 1
  if dist_number_fraction_permil(s, 0 - 1) != DIST_INVALID { ok10 = 0 }
  if dist_number_fraction_permil(s, 1001) != DIST_INVALID { ok10 = 0 }
  if dist_derived_coupling(s, 0) != DIST_INVALID { ok10 = 0 }
  if dist_profile_is_reference() != 1 { ok10 = 0 }
  let bad: *IceDist = dist_new(2)
  dist_set(bad, 0, 300, 10)
  dist_set(bad, 1, 100, 10)
  if dist_count_melted(bad, 100) != DIST_INVALID { ok10 = 0 }
  tw("T10 out-of-range phi refused, descending bins refused, reference profile flagged: " as *u8)
  if ok10 == 1 { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
173
  // --- T11 CROSS-ORGAN AGREEMENT.  Feeding the DERIVED coupling into
  //         nx_ice_recrystal must produce more growth than the asserted one
  //         did, by the margin T5 measured.  The two organs are independent
  //         paths to the same quantity, so agreement is evidence. ---
  total = total + 1
  let with_asserted: i64 = ir_size_after_cycles(250, phi, 10)
  let growth_derived: i64 = dist_volume_growth_permil(s, phi)
  var v: i64 = 250 * 250 * 250
  var c: i64 = 0
  while c < 10 { v = v + v * growth_derived / 1000; c = c + 1 }
  let with_derived: i64 = ir_icbrt(v)
  tw("T11 after 10 cycles: asserted coupling gives D=" as *u8); tn(with_asserted)
  tw(", derived coupling gives D=" as *u8); tn(with_derived)
  tw(" -- the assertion was optimistic: " as *u8)
  if with_derived > with_asserted { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
189
  // --- T12 ***THE CORRECTION TO A PUBLISHED NUMBER.***  Wave 26 published
  //         the realistic -20/-16 C case (33 permil of the ice cycling,
  //         17 excursions over 60 days) using the ASSERTED coupling and
  //         reported 43.6 um.  Recomputed with the coupling derived from
  //         the distribution, the real figure is worse.  Both are printed
  //         so the size of the correction is visible rather than quietly
  //         replaced. ---
  total = total + 1
  let phi_real: i64 = 33
  let g_real: i64 = dist_volume_growth_permil(s, phi_real)
  let pub: i64 = ir_size_combined(250, 537500, 60, phi_real, 17)
  let corrected: i64 = ir_size_combined_growth(250, 537500, 60, g_real, 17)
  tw("T12 realistic -20/-16C over 60d: published(asserted coupling) D=" as *u8); tn(pub)
  tw("  corrected(derived coupling) D=" as *u8); tn(corrected)
  tw("  per-cycle growth=" as *u8); tn(g_real); tw(" permil; grades " as *u8)
  tn(ir_texture_grade(pub)); tw(" -> " as *u8); tn(ir_texture_grade(corrected)); tw(": " as *u8)
  var ok12: i64 = 1
  if g_real <= 0 { ok12 = 0 }
  if corrected <= pub { ok12 = 0 }
  if ir_texture_grade(corrected) < ir_texture_grade(pub) { ok12 = 0 }
  if ok12 == 1 { pass = pass + 1; tw("PASS\n" as *u8) } else { tw("FAIL\n" as *u8) }
211
  tw("ICE-DISTRIBUTION-GATE passed " as *u8); tn(pass); tw("/" as *u8); tn(total)
  if pass == total { tw(" verdict=GREEN\n" as *u8); sys_exit(0); return 0 }
  tw(" verdict=RED\n" as *u8); sys_exit(1); return 1
215}
nx_ice_distribution_test.nx source

`nx_ice_distribution_test.nx` source
