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    {
      "cell_type": "code",
      "execution_count": null,
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      "source": [
        "%matplotlib inline"
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      "cell_type": "markdown",
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      "source": [
        "\n# Plot classification probability\n\n\nPlot the classification probability for different classifiers. We use a 3\nclass dataset, and we classify it with a Support Vector classifier, L1\nand L2 penalized logistic regression with either a One-Vs-Rest or multinomial\nsetting, and Gaussian process classification.\n\nThe logistic regression is not a multiclass classifier out of the box. As\na result it can identify only the first class.\n\n"
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    {
      "cell_type": "code",
      "execution_count": null,
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      "source": [
        "print(__doc__)\n\n# Author: Alexandre Gramfort <alexandre.gramfort@inria.fr>\n# License: BSD 3 clause\n\nimport matplotlib.pyplot as plt\nimport numpy as np\n\nfrom sklearn.linear_model import LogisticRegression\nfrom sklearn.svm import SVC\nfrom sklearn.gaussian_process import GaussianProcessClassifier\nfrom sklearn.gaussian_process.kernels import RBF\nfrom sklearn import datasets\n\niris = datasets.load_iris()\nX = iris.data[:, 0:2]  # we only take the first two features for visualization\ny = iris.target\n\nn_features = X.shape[1]\n\nC = 1.0\nkernel = 1.0 * RBF([1.0, 1.0])  # for GPC\n\n# Create different classifiers. The logistic regression cannot do\n# multiclass out of the box.\nclassifiers = {'L1 logistic': LogisticRegression(C=C, penalty='l1'),\n               'L2 logistic (OvR)': LogisticRegression(C=C, penalty='l2'),\n               'Linear SVC': SVC(kernel='linear', C=C, probability=True,\n                                 random_state=0),\n               'L2 logistic (Multinomial)': LogisticRegression(\n                C=C, solver='lbfgs', multi_class='multinomial'),\n               'GPC': GaussianProcessClassifier(kernel)\n               }\n\nn_classifiers = len(classifiers)\n\nplt.figure(figsize=(3 * 2, n_classifiers * 2))\nplt.subplots_adjust(bottom=.2, top=.95)\n\nxx = np.linspace(3, 9, 100)\nyy = np.linspace(1, 5, 100).T\nxx, yy = np.meshgrid(xx, yy)\nXfull = np.c_[xx.ravel(), yy.ravel()]\n\nfor index, (name, classifier) in enumerate(classifiers.items()):\n    classifier.fit(X, y)\n\n    y_pred = classifier.predict(X)\n    classif_rate = np.mean(y_pred.ravel() == y.ravel()) * 100\n    print(\"classif_rate for %s : %f \" % (name, classif_rate))\n\n    # View probabilities=\n    probas = classifier.predict_proba(Xfull)\n    n_classes = np.unique(y_pred).size\n    for k in range(n_classes):\n        plt.subplot(n_classifiers, n_classes, index * n_classes + k + 1)\n        plt.title(\"Class %d\" % k)\n        if k == 0:\n            plt.ylabel(name)\n        imshow_handle = plt.imshow(probas[:, k].reshape((100, 100)),\n                                   extent=(3, 9, 1, 5), origin='lower')\n        plt.xticks(())\n        plt.yticks(())\n        idx = (y_pred == k)\n        if idx.any():\n            plt.scatter(X[idx, 0], X[idx, 1], marker='o', c='k')\n\nax = plt.axes([0.15, 0.04, 0.7, 0.05])\nplt.title(\"Probability\")\nplt.colorbar(imshow_handle, cax=ax, orientation='horizontal')\n\nplt.show()"
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