From 8a77cd74846f972cd1721fbefa130618ac03e048 Mon Sep 17 00:00:00 2001
From: Aaron Fenyes <aaron.fenyes@fareycircles.ooo>
Date: Thu, 18 Jul 2024 03:21:46 -0700
Subject: [PATCH] Irisawa hexlet: drop unviable approach

The approach in the deleted file can't work, because the "sun" and
"moon" spheres can't be placed arbitrarily.
---
 engine-proto/gram-test/irisawa-hexlet_bad.jl | 105 -------------------
 1 file changed, 105 deletions(-)
 delete mode 100644 engine-proto/gram-test/irisawa-hexlet_bad.jl

diff --git a/engine-proto/gram-test/irisawa-hexlet_bad.jl b/engine-proto/gram-test/irisawa-hexlet_bad.jl
deleted file mode 100644
index 8786778..0000000
--- a/engine-proto/gram-test/irisawa-hexlet_bad.jl
+++ /dev/null
@@ -1,105 +0,0 @@
-include("Engine.jl")
-
-using SparseArrays
-
-# --- construct the nucleus spheres ---
-
-println("--- Nucleus spheres ---\n")
-
-# initialize the partial gram matrix for the circumscribing and nucleus spheres
-J = Int64[]
-K = Int64[]
-values = BigFloat[]
-for n in 1:3
-  push!(J, n)
-  push!(K, n)
-  push!(values, 1)
-  if n > 1
-    append!(J, [1, n])
-    append!(K, [n, 1])
-    append!(values, [1, 1])
-  end
-end
-gram_nuc = sparse(J, K, values)
-
-# make an initial guess
-guess_nuc = hcat(
-  Engine.sphere(BigFloat[0, 0, 0], BigFloat(15)),
-  Engine.sphere(BigFloat[0, 0, -10], BigFloat(5)),
-  Engine.sphere(BigFloat[0, 0, 11], BigFloat(3)),
-)
-frozen_nuc = [CartesianIndex(4, k) for k in 1:3]
-
-# complete the gram matrix using Newton's method with backtracking
-L_nuc, success_nuc, history_nuc = Engine.realize_gram(gram_nuc, guess_nuc, frozen_nuc)
-completed_gram_nuc = L_nuc'*Engine.Q*L_nuc
-println("Completed Gram matrix:\n")
-display(completed_gram_nuc)
-if success_nuc
-  println("\nTarget accuracy achieved!")
-else
-  println("\nFailed to reach target accuracy")
-end
-println("Steps: ", size(history_nuc.scaled_loss, 1))
-println("Loss: ", history_nuc.scaled_loss[end], "\n")
-
-# --- construct the chain of spheres ---
-
-# initialize the partial gram matrix for the chain of spheres
-J = Int64[]
-K = Int64[]
-values = BigFloat[]
-for a in 4:9
-  push!(J, a)
-  push!(K, a)
-  push!(values, 1)
-  
-  # each chain sphere is internally tangent to the circumscribing sphere
-  append!(J, [a, 1])
-  append!(K, [1, a])
-  append!(values, [1, 1])
-  
-  # each chain sphere is externally tangent to the nucleus spheres
-  for n in 2:3
-    append!(J, [a, n])
-    append!(K, [n, a])
-    append!(values, [-1, -1])
-  end
-  
-  # each chain sphere is externally tangent to the next sphere in the chain
-  #=
-  a_next = 4 + mod(a-3, 6)
-  append!(J, [a, a_next])
-  append!(K, [a_next, a])
-  append!(values, [-1, -1])
-  =#
-end
-gram_chain = sparse(J, K, values)
-
-if success_nuc
-  println("--- Chain spheres ---\n")
-  
-  # make an initial guess, with the circumscribing and nucleus spheres included
-  # as frozen elements
-  guess_chain = hcat(
-    L_nuc,
-    (
-      Engine.sphere(10*BigFloat[cos(k*π/3), sin(k*π/3), 0], BigFloat(2.5))
-      for k in 1:6
-    )...
-  )
-  frozen_chain = [CartesianIndex(j, k) for k in 1:3 for j in 1:5]
-  
-  # complete the gram matrix using Newton's method with backtracking
-  L_chain, success_chain, history_chain = Engine.realize_gram(gram_chain, guess_chain, frozen_chain)
-  completed_gram_chain = L_chain'*Engine.Q*L_chain
-  println("Completed Gram matrix:\n")
-  display(completed_gram_chain)
-  if success_chain
-    println("\nTarget accuracy achieved!")
-  else
-    println("\nFailed to reach target accuracy")
-  end
-  println("Steps: ", size(history_chain.scaled_loss, 1))
-  println("Loss: ", history_chain.scaled_loss[end], "\n")
-end
\ No newline at end of file