Symulowanie-wizualne/sw_lab3.ipynb

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2022-12-08 21:38:03 +01:00
{
"cells": [
{
"cell_type": "code",
"execution_count": 1,
"id": "32d973e1",
"metadata": {},
"outputs": [],
"source": [
"from load_data import get_dataset\n",
"import numpy as np\n",
"from tabulate import tabulate\n",
"\n",
"X_train, y_train, X_test, y_test = get_dataset(new_size=64)"
]
},
{
"cell_type": "markdown",
"id": "e63a5e75-7a26-4a97-b53d-67b858345126",
"metadata": {},
"source": [
"# Zadanie 1 (2 pkt)\n",
"\n",
"Rozwiń algorytm regresji logistycznej z lab. 1, wprowadzając do niego człon regularyzacyjny."
]
},
{
"cell_type": "code",
"execution_count": 2,
"id": "ea300c45",
"metadata": {},
"outputs": [],
"source": [
"class LogisticRegression():\n",
" def __init__(self, l2=1):\n",
" self.l2 = l2\n",
"\n",
" def mapY(self, y, cls):\n",
" m = len(y)\n",
" yBi = np.matrix(np.zeros(m)).reshape(m, 1)\n",
" yBi[y == cls] = 1.\n",
" return yBi\n",
"\n",
" def indicatorMatrix(self, y):\n",
" classes = np.unique(y.tolist())\n",
" m, k = len(y), len(classes)\n",
" # k = len(classes)\n",
" Y = np.matrix(np.zeros((m, k)))\n",
" for i, cls in enumerate(classes):\n",
" Y[:, i] = self.mapY(y, cls)\n",
" return Y\n",
" \n",
" # Zapis macierzowy funkcji softmax\n",
" def softmax(self, X):\n",
" return np.exp(X) / np.sum(np.exp(X))\n",
" \n",
" # Funkcja regresji logistcznej\n",
" def h(self, theta, X):\n",
" return 1.0 /(1.0 + np.exp(-X * theta))\n",
" \n",
" # Funkcja kosztu dla regresji logistycznej\n",
" def J(self, h, theta, X, y):\n",
" m = len(y)\n",
" h_val = h(theta, X)\n",
" s1 = np.multiply(y, np.log(h_val))\n",
" s2 = np.multiply((1 - y), np.log(1 - h_val))\n",
" s3 = np.sum(s1+s2, axis=0)/m\n",
" s4 = (self.l2 * np.sum(np.square(theta))) / 2*m\n",
" return -s3 + s4\n",
"\n",
" # Gradient dla regresji logistycznej\n",
" def dJ(self, h, theta, X, y):\n",
" return 1.0 / (self.l2/len(y)) * (X.T * (h(theta, X) - y))\n",
"\n",
" # Metoda gradientu prostego dla regresji logistycznej\n",
" def GD(self, h, fJ, fdJ, theta, X, y, alpha=0.01, eps=10**-3, maxSteps=1000):\n",
" errorCurr = fJ(h, theta, X, y)\n",
" errors = [[errorCurr, theta]]\n",
" while True:\n",
" # oblicz nowe theta\n",
" theta = theta - alpha * fdJ(h, theta, X, y)\n",
" # raportuj poziom błędu\n",
" errorCurr, errorPrev = fJ(h, theta, X, y), errorCurr\n",
" # kryteria stopu\n",
" if abs(errorPrev - errorCurr) <= eps:\n",
" break\n",
" if len(errors) > maxSteps:\n",
" break\n",
" errors.append([errorCurr, theta]) \n",
" # return theta, errors\n",
" return theta\n",
"\n",
" def trainMaxEnt(self, X, Y):\n",
" n = X.shape[1]\n",
" thetas = []\n",
" for c in range(Y.shape[1]):\n",
" YBi = Y[:,c]\n",
" theta = np.matrix(np.random.random(n)).reshape(n,1)\n",
" # Macierz parametrów theta obliczona dla każdej klasy osobno.\n",
" # thetaBest, errors = self.GD(self.h, self.J, self.dJ, theta, \n",
" # X, YBi, alpha=0.1, eps=10**-4)\n",
" # thetas.append(thetaBest)\n",
" thetas.append(self.GD(self.h, self.J, self.dJ, theta, X, YBi, alpha=0.1, eps=10**-4))\n",
" return thetas\n",
"\n",
" def classify(self, thetas, X):\n",
" regs = np.array([(X*theta).item() for theta in thetas])\n",
" return np.argmax(self.softmax(regs))\n",
" # probs = self.softmax(regs)\n",
" # result = np.argmax(probs)\n",
" # return result\n",
"\n",
" def class_score(self, expected, predicted):\n",
" # accuracy = TP + TN / FP + FN + TP + TN\n",
" accuracy = sum(1 for exp, pred in zip(expected, predicted) if exp == pred) / len(expected)\n",
" # precision = TP / FP + TP\n",
" precision = sum(\n",
" 1 for exp, pred in zip(expected, predicted) if exp == 1.0 and pred == 1.0) / sum(\n",
" 1 for exp, pred in zip(expected, predicted) if exp == 1.0)\n",
" # recall = TP / FN + TP\n",
" recall = sum(\n",
" 1 for exp, pred in zip(expected, predicted) if exp == 1.0 and pred == 1.0) / sum(\n",
" 1 for exp, pred in zip(expected, predicted) if pred == 1.0)\n",
" f1 = (2 * precision * recall) / (precision + recall)\n",
" return accuracy, precision, recall, f1\n",
"\n",
" def fit(self, X_train, y_train):\n",
" # Y = self.indicatorMatrix(y_train)\n",
" # self.thetas = self.trainMaxEnt(X_train, Y)\n",
" self.thetas = self.trainMaxEnt(X_train, self.indicatorMatrix(y_train))\n",
"\n",
" def predict(self, X_test):\n",
" return np.array([self.classify(self.thetas, x) for x in X_test])\n",
"\n",
" def accuracy(self, expected, predicted):\n",
" return sum(1 for x, y in zip(expected, predicted) if x == y) / len(expected)"
]
},
{
"cell_type": "code",
"execution_count": 3,
"id": "84fc2187",
"metadata": {},
"outputs": [
{
"name": "stderr",
"output_type": "stream",
"text": [
"/var/folders/3r/c8tg1h051m18qhsdccdysrt40000gn/T/ipykernel_43367/551403934.py:33: RuntimeWarning: divide by zero encountered in log\n",
" s2 = np.multiply((1 - y), np.log(1 - h_val))\n",
"/var/folders/3r/c8tg1h051m18qhsdccdysrt40000gn/T/ipykernel_43367/551403934.py:33: RuntimeWarning: invalid value encountered in multiply\n",
" s2 = np.multiply((1 - y), np.log(1 - h_val))\n",
"/var/folders/3r/c8tg1h051m18qhsdccdysrt40000gn/T/ipykernel_43367/551403934.py:26: RuntimeWarning: overflow encountered in exp\n",
" return 1.0 /(1.0 + np.exp(-X * theta))\n",
"/var/folders/3r/c8tg1h051m18qhsdccdysrt40000gn/T/ipykernel_43367/551403934.py:32: RuntimeWarning: divide by zero encountered in log\n",
" s1 = np.multiply(y, np.log(h_val))\n",
"/var/folders/3r/c8tg1h051m18qhsdccdysrt40000gn/T/ipykernel_43367/551403934.py:32: RuntimeWarning: invalid value encountered in multiply\n",
" s1 = np.multiply(y, np.log(h_val))\n"
]
}
],
"source": [
"# 16x16, l2=0.01 -> 5m 11.4s\n",
"# 32x32, l2=0.1 -> 20m 31.3s\n",
"# 64x64, l2=0.1 -> 219m 10.8s\n",
"logreg = LogisticRegression(l2=0.1)\n",
"logreg.fit(X_train, y_train)"
]
},
{
"cell_type": "code",
"execution_count": 4,
"id": "f2a4b169",
"metadata": {},
"outputs": [
{
"name": "stderr",
"output_type": "stream",
"text": [
"/var/folders/3r/c8tg1h051m18qhsdccdysrt40000gn/T/ipykernel_43367/551403934.py:22: RuntimeWarning: invalid value encountered in true_divide\n",
" return np.exp(X) / np.sum(np.exp(X))\n",
"/var/folders/3r/c8tg1h051m18qhsdccdysrt40000gn/T/ipykernel_43367/551403934.py:22: RuntimeWarning: overflow encountered in exp\n",
" return np.exp(X) / np.sum(np.exp(X))\n"
]
},
{
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"execution_count": 4,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"logreg.accuracy(y_test, logreg.predict(X_test))"
]
},
{
"cell_type": "markdown",
"id": "945d1169-a13c-44a5-ad51-73ec62438487",
"metadata": {},
"source": [
"# Zadanie 2 (4 pkt)\n",
"\n",
"Zaimplementuj algorytm SVM z miękkim marginesem (regularyzacją)."
]
},
{
"cell_type": "code",
"execution_count": 5,
"id": "7a58dff1-f85d-4e07-b5e4-b639fc2af3ac",
"metadata": {
"deletable": false,
"nbgrader": {
"cell_type": "code",
"checksum": "d0e86f0fc352ea3a95940ad21ba9cd6c",
"grade": true,
"grade_id": "cell-2e22217733fd5f34",
"locked": false,
"points": 4,
"schema_version": 3,
"solution": true,
"task": false
}
},
"outputs": [],
"source": [
"class SVM():\n",
" def __init__(self, lr=0.001, lambda_param=10**-6, n_iters=1000):\n",
" self.lr = lr\n",
" self.lambda_param = lambda_param\n",
" self.n_iters = n_iters\n",
"\n",
" def _mapY(self, y, cls):\n",
" m = len(y)\n",
" yBi = np.matrix(np.zeros(m)).reshape(m, 1)\n",
" yBi[y == cls] = 1.\n",
" return yBi\n",
"\n",
" def _indicatorMatrix(self, y):\n",
" classes = np.unique(y.tolist())\n",
" m, k = len(y), len(classes)\n",
" Y = np.matrix(np.zeros((m, k)))\n",
" for i, cls in enumerate(classes):\n",
" Y[:, i] = self._mapY(y, cls)\n",
" return Y\n",
"\n",
" def fit(self, X, y):\n",
" n_classes = len(np.unique(y))\n",
" y = self._indicatorMatrix(y)\n",
" y = np.where(y == 0, -1, 1)\n",
"\n",
" n_features = X.shape[1]\n",
" self.weights, self.biases = [], []\n",
"\n",
" for cls in range(n_classes):\n",
" y_ = y[:,cls]\n",
" y_ = np.where(y_ <= 0, -1, 1)\n",
"\n",
" w, b = np.zeros(n_features), 0\n",
"\n",
" for _ in range(self.n_iters):\n",
" for idx, x_i in enumerate(X):\n",
" condition = y_[idx] * (np.dot(x_i, w) - b) >= 1\n",
" if condition:\n",
" w -= self.lr * (2 * self.lambda_param * w)\n",
" else:\n",
" w -= self.lr * (2 * self.lambda_param * w - np.dot(x_i, y_[idx]))\n",
" b -= self.lr * y_[idx]\n",
" self.weights.append(w)\n",
" self.biases.append(b)\n",
"\n",
" def _classify(self, x):\n",
" cls = [np.sign(np.dot(x, self.weights[i]) - self.biases[i]) for i in range(len(self.biases))]\n",
" return cls.index(1.0) if 1.0 in cls else 0\n",
"\n",
" def predict(self, X):\n",
" return list(map(lambda x: self._classify(x), X))\n",
"\n",
" def accuracy(self, expected, predicted):\n",
" return sum(1 for x, y in zip(expected, predicted) if x == y) / len(expected)"
]
},
{
"cell_type": "code",
"execution_count": 6,
"id": "62857aa5",
"metadata": {},
"outputs": [],
"source": [
"# 16x16 -> 1m 28.8s\n",
"# 32x32 -> 2m 2.2s\n",
"# 64x64 -> 4m 55.3s\n",
"\n",
"svm = SVM()\n",
"svm.fit(X_train, y_train)\n"
]
},
{
"cell_type": "code",
"execution_count": 7,
"id": "27bdbf4f",
"metadata": {},
"outputs": [
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"execution_count": 7,
"metadata": {},
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],
"source": [
"svm.accuracy(y_test, svm.predict(X_test))"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "0aa0c9d6",
"metadata": {},
"outputs": [],
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}
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