Cartesian index

cartesian.ipynb

{
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   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "2×3×4 CartesianIndices{3,Tuple{Base.OneTo{Int64},Base.OneTo{Int64},Base.OneTo{Int64}}}:\n",
       "[:, :, 1] =\n",
       " CartesianIndex(1, 1, 1)  CartesianIndex(1, 2, 1)  CartesianIndex(1, 3, 1)\n",
       " CartesianIndex(2, 1, 1)  CartesianIndex(2, 2, 1)  CartesianIndex(2, 3, 1)\n",
       "\n",
       "[:, :, 2] =\n",
       " CartesianIndex(1, 1, 2)  CartesianIndex(1, 2, 2)  CartesianIndex(1, 3, 2)\n",
       " CartesianIndex(2, 1, 2)  CartesianIndex(2, 2, 2)  CartesianIndex(2, 3, 2)\n",
       "\n",
       "[:, :, 3] =\n",
       " CartesianIndex(1, 1, 3)  CartesianIndex(1, 2, 3)  CartesianIndex(1, 3, 3)\n",
       " CartesianIndex(2, 1, 3)  CartesianIndex(2, 2, 3)  CartesianIndex(2, 3, 3)\n",
       "\n",
       "[:, :, 4] =\n",
       " CartesianIndex(1, 1, 4)  CartesianIndex(1, 2, 4)  CartesianIndex(1, 3, 4)\n",
       " CartesianIndex(2, 1, 4)  CartesianIndex(2, 2, 4)  CartesianIndex(2, 3, 4)"
      ]
     },
     "execution_count": 1,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "CIs = CartesianIndices((2, 3, 4))\n",
    "\n",
    "# 配列からも生成できる\n",
    "#X = rand(2, 3, 4)\n",
    "#CIs = CartesianIndices(X)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(i, j, k) = CI.I = (1, 1, 1)\n",
      "(i, j, k) = CI.I = (2, 1, 1)\n",
      "(i, j, k) = CI.I = (1, 2, 1)\n",
      "(i, j, k) = CI.I = (2, 2, 1)\n",
      "(i, j, k) = CI.I = (1, 3, 1)\n",
      "(i, j, k) = CI.I = (2, 3, 1)\n",
      "(i, j, k) = CI.I = (1, 1, 2)\n",
      "(i, j, k) = CI.I = (2, 1, 2)\n",
      "(i, j, k) = CI.I = (1, 2, 2)\n",
      "(i, j, k) = CI.I = (2, 2, 2)\n",
      "(i, j, k) = CI.I = (1, 3, 2)\n",
      "(i, j, k) = CI.I = (2, 3, 2)\n",
      "(i, j, k) = CI.I = (1, 1, 3)\n",
      "(i, j, k) = CI.I = (2, 1, 3)\n",
      "(i, j, k) = CI.I = (1, 2, 3)\n",
      "(i, j, k) = CI.I = (2, 2, 3)\n",
      "(i, j, k) = CI.I = (1, 3, 3)\n",
      "(i, j, k) = CI.I = (2, 3, 3)\n",
      "(i, j, k) = CI.I = (1, 1, 4)\n",
      "(i, j, k) = CI.I = (2, 1, 4)\n",
      "(i, j, k) = CI.I = (1, 2, 4)\n",
      "(i, j, k) = CI.I = (2, 2, 4)\n",
      "(i, j, k) = CI.I = (1, 3, 4)\n",
      "(i, j, k) = CI.I = (2, 3, 4)\n"
     ]
    }
   ],
   "source": [
    "# 逐次的に得られればよいなら\n",
    "\n",
    "for CI in CIs\n",
    "    @show i, j, k = CI.I\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "scrolled": true
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "2×3×4 Array{Tuple{Int64,Int64,Int64},3}:\n",
       "[:, :, 1] =\n",
       " (1, 1, 1)  (1, 2, 1)  (1, 3, 1)\n",
       " (2, 1, 1)  (2, 2, 1)  (2, 3, 1)\n",
       "\n",
       "[:, :, 2] =\n",
       " (1, 1, 2)  (1, 2, 2)  (1, 3, 2)\n",
       " (2, 1, 2)  (2, 2, 2)  (2, 3, 2)\n",
       "\n",
       "[:, :, 3] =\n",
       " (1, 1, 3)  (1, 2, 3)  (1, 3, 3)\n",
       " (2, 1, 3)  (2, 2, 3)  (2, 3, 3)\n",
       "\n",
       "[:, :, 4] =\n",
       " (1, 1, 4)  (1, 2, 4)  (1, 3, 4)\n",
       " (2, 1, 4)  (2, 2, 4)  (2, 3, 4)"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# タプルの配列として得たいなら\n",
    "\n",
    "getproperty.(CIs, :I)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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