{"id":3022,"date":"2022-02-20T21:52:08","date_gmt":"2022-02-20T13:52:08","guid":{"rendered":"https:\/\/egonlin.com\/?p=3022"},"modified":"2022-02-20T21:52:08","modified_gmt":"2022-02-20T13:52:08","slug":"%e7%ac%ac%e5%9b%9b%e8%8a%82%ef%bc%9alogistic%e5%9b%9e%e5%bd%92","status":"publish","type":"post","link":"https:\/\/egonlin.com\/?p=3022","title":{"rendered":"\u7b2c\u56db\u8282\uff1aLogistic\u56de\u5f52"},"content":{"rendered":"

Logistic\u56de\u5f52(\u9e22\u5c3e\u82b1\u5206\u7c7b)<\/h1>\n

\u5bfc\u5165\u6a21\u5757<\/h1>\n

\"\"<\/div><\/p>\n
import numpy as np\nimport matplotlib.pyplot as plt\nfrom matplotlib.colors import ListedColormap\nfrom matplotlib.font_manager import FontProperties\nfrom sklearn import datasets\nfrom sklearn.linear_model import LogisticRegression\n%matplotlib inline\nfont = FontProperties(fname='\/Library\/Fonts\/Heiti.ttc')<\/code><\/pre>\n
\u83b7\u53d6\u6570\u636e<\/h1>\n
iris_data = datasets.load_iris()\nX = iris_data.data[:, [2, 3]]\ny = iris_data.target\nlabel_list = ['\u5c71\u9e22\u5c3e', '\u6742\u8272\u9e22\u5c3e', '\u7ef4\u5409\u5c3c\u4e9a\u9e22\u5c3e']<\/code><\/pre>\n
\u6784\u5efa\u51b3\u7b56\u8fb9\u754c<\/h1>\n
def plot_decision_regions(X, y, classifier=None):\n    marker_list = ['o', 'x', 's']\n    color_list = ['r', 'b', 'g']\n    cmap = ListedColormap(color_list[:len(np.unique(y))])\n\n    x1_min, x1_max = X[:, 0].min()-1, X[:, 0].max()+1\n    x2_min, x2_max = X[:, 1].min()-1, X[:, 1].max()+1\n    t1 = np.linspace(x1_min, x1_max, 666)\n    t2 = np.linspace(x2_min, x2_max, 666)\n\n    x1, x2 = np.meshgrid(t1, t2)\n    y_hat = classifier.predict(np.array([x1.ravel(), x2.ravel()]).T)\n    y_hat = y_hat.reshape(x1.shape)\n    plt.contourf(x1, x2, y_hat, alpha=0.2, cmap=cmap)\n    plt.xlim(x1_min, x1_max)\n    plt.ylim(x2_min, x2_max)\n\n    for ind, clas in enumerate(np.unique(y)):\n        plt.scatter(X[y == clas, 0], X[y == clas, 1], alpha=0.8, s=50,\n                    c=color_list[ind], marker=marker_list[ind], label=label_list[clas])<\/code><\/pre>\n
\u8bad\u7ec3\u6a21\u578b<\/h1>\n
# C\u4e0e\u6b63\u5219\u5316\u53c2\u6570\u03bb\u6210\u53cd\u6bd4\uff0c\u5373\u51cf\u5c0f\u53c2\u6570C\u589e\u5927\u6b63\u5219\u5316\u7684\u5f3a\u5ea6\n# lbfgs\u4f7f\u7528\u62df\u725b\u987f\u6cd5\u4f18\u5316\u53c2\u6570\n# \u5206\u7c7b\u65b9\u5f0f\u4e3aOvR\uff08One-vs-Rest\uff09\nlr = LogisticRegression(C=100, random_state=1,\n                        solver='lbfgs', multi_class='ovr')\nlr.fit(X, y)<\/code><\/pre>\n
LogisticRegression(C=100, class_weight=None, dual=False, fit_intercept=True,\n          intercept_scaling=1, max_iter=100, multi_class='ovr',\n          n_jobs=None, penalty='l2', random_state=1, solver='lbfgs',\n          tol=0.0001, verbose=0, warm_start=False)<\/code><\/pre>\n
C\u53c2\u6570\u4e0e\u6743\u91cd\u7cfb\u6570\u7684\u5173\u7cfb<\/h2>\n
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\u67e5\u770b\u66f4\u591a<\/h2>
\u8054\u7cfb\u7ba1\u7406\u5458\u5fae\u4fe1tutu19192010\uff0c\u6ce8\u518c\u8d26\u53f7<\/p>\n<\/div>
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Logistic\u56de\u5f52(\u9e22\u5c3e\u82b1\u5206\u7c7b) \u5bfc\u5165\u6a21\u5757 import numpy as np import matplo […]<\/p>\n","protected":false},"author":3,"featured_media":3024,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[276,287],"tags":[],"_links":{"self":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/3022"}],"collection":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3022"}],"version-history":[{"count":0,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/3022\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/media\/3024"}],"wp:attachment":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3022"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3022"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3022"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}