computational-graph-is-only-built-once.ipynb

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   "cell_type": "markdown",
   "id": "aerial-clock",
   "metadata": {},
   "source": [
    "# computational-graph-is-only-built-once/113923"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "distinguished-stopping",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1.8.0\n"
     ]
    }
   ],
   "source": [
    "import torch\n",
    "import torch.nn as nn\n",
    "import torch.nn.functional as F\n",
    "\n",
    "print(torch.__version__)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "sublime-outside",
   "metadata": {},
   "outputs": [],
   "source": [
    "m = nn.Linear(4, 2)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "urban-contractor",
   "metadata": {},
   "outputs": [],
   "source": [
    "loss = None\n",
    "\n",
    "for _ in range(5):\n",
    "    x = torch.rand(4, 4)\n",
    "    cur_loss = m(x).sum()\n",
    "    if loss is None:\n",
    "        loss = cur_loss\n",
    "    else:\n",
    "        loss += cur_loss\n",
    "loss.backward()"
   ]
  }
 ],
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