GJP open (Random walk forecast).ipynb

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   "source": [
    "import pandas as pd\n",
    "import numpy as np\n",
    "import random\n",
    "import matplotlib.pyplot as plt\n",
    "import scipy\n",
    "#https://www.gjopen.com/questions/1045-what-will-be-the-closing-spot-price-for-an-ounce-of-gold-against-the-us-dollar-on-28-december-2018"
   ]
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   "source": [
    "from random import seed\n",
    "from random import random\n",
    "from sklearn.metrics import mean_squared_error"
   ]
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   "execution_count": 11,
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   "source": [
    "df = pd.read_csv('XAU_USD Historical Data.csv')\n",
    "pricesstr = df['Price']\n",
    "#create uncleaned array of prices from the CSV"
   ]
  },
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    "prices = []"
   ]
  },
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   "source": [
    "for i in pricesstr:\n",
    "    out = float(i.replace(',',''))\n",
    "    prices.append(out)\n",
    "    \n",
    "#clean up the data which is both in str and has commas that cause errors"
   ]
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    "pricesSTD = np.std(prices)\n",
    "pricesSTD\n",
    "#standard deviation"
   ]
  },
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   "cell_type": "code",
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   "source": [
    "step = np.average(np.diff(prices))\n",
    "#defines step to take during random walk predictions"
   ]
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    "testErrors = []\n",
    "for i in range(0,9999):\n",
    "    train_size = int(len(prices) * 0.66)\n",
    "    train, test = prices[0:train_size], prices[train_size:]\n",
    "    # random prediction\n",
    "    predictions = list()\n",
    "    history = train[-1]\n",
    "    for i in range(len(test)):\n",
    "        yhat = history + ((-(step)) if random() < 0.5 else step)\n",
    "        predictions.append(yhat)\n",
    "        history = test[i]\n",
    "    error = mean_squared_error(test, predictions)\n",
    "    testErrors.append(error)\n",
    "print(np.average(testErrors))\n",
    "errorrate = np.average(testErrors)\n",
    "#tests multipule random walks for accuracy and averages the error rate"
   ]
  },
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    "startPoint = df.iloc[0][1]\n",
    "startPoint = float(startPoint.replace(',',''))"
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    "print(str(startPoint) + '\\n')\n",
    "display((startPoint-errorrate),(startPoint+errorrate))\n",
    "print('')\n",
    "display((startPoint-pricesSTD),(startPoint+pricesSTD))\n",
    "print('')\n",
    "display((startPoint-2 * pricesSTD),(startPoint+2 * pricesSTD))\n",
    "print('')\n",
    "display((startPoint-3 * pricesSTD),(startPoint+3 * pricesSTD))"
   ]
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