dev/notebooks/auto_examples/cluster/plot_agglomerative_dendrogram.ipynb

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        "\n# Plot Hierarchical Clustering Dendrogram\nThis example plots the corresponding dendrogram of a hierarchical clustering\nusing AgglomerativeClustering and the dendrogram method available in scipy.\n"
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      "source": [
        "import numpy as np\nfrom matplotlib import pyplot as plt\nfrom scipy.cluster.hierarchy import dendrogram\n\nfrom sklearn.cluster import AgglomerativeClustering\nfrom sklearn.datasets import load_iris\n\n\ndef plot_dendrogram(model, **kwargs):\n    # Create linkage matrix and then plot the dendrogram\n\n    # create the counts of samples under each node\n    counts = np.zeros(model.children_.shape[0])\n    n_samples = len(model.labels_)\n    for i, merge in enumerate(model.children_):\n        current_count = 0\n        for child_idx in merge:\n            if child_idx < n_samples:\n                current_count += 1  # leaf node\n            else:\n                current_count += counts[child_idx - n_samples]\n        counts[i] = current_count\n\n    linkage_matrix = np.column_stack(\n        [model.children_, model.distances_, counts]\n    ).astype(float)\n\n    # Plot the corresponding dendrogram\n    dendrogram(linkage_matrix, **kwargs)\n\n\niris = load_iris()\nX = iris.data\n\n# setting distance_threshold=0 ensures we compute the full tree.\nmodel = AgglomerativeClustering(distance_threshold=0, n_clusters=None)\n\nmodel = model.fit(X)\nplt.title(\"Hierarchical Clustering Dendrogram\")\n# plot the top three levels of the dendrogram\nplot_dendrogram(model, truncate_mode=\"level\", p=3)\nplt.xlabel(\"Number of points in node (or index of point if no parenthesis).\")\nplt.show()"
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