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k-means in Tensorflow
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import tensorflow as tf | |
import numpy as np | |
import time | |
N=10000 | |
K=4 | |
MAX_ITERS = 1000 | |
start = time.time() | |
points = tf.Variable(tf.random_uniform([N,2])) | |
cluster_assignments = tf.Variable(tf.zeros([N], dtype=tf.int64)) | |
# Silly initialization: Use the first K points as the starting | |
# centroids. In the real world, do this better. | |
centroids = tf.Variable(tf.slice(points.initialized_value(), [0,0], [K,2])) | |
# Replicate to N copies of each centroid and K copies of each | |
# point, then subtract and compute the sum of squared distances. | |
rep_centroids = tf.reshape(tf.tile(centroids, [N, 1]), [N, K, 2]) | |
rep_points = tf.reshape(tf.tile(points, [1, K]), [N, K, 2]) | |
sum_squares = tf.reduce_sum(tf.square(rep_points - rep_centroids), | |
reduction_indices=2) | |
# Use argmin to select the lowest-distance point | |
best_centroids = tf.argmin(sum_squares, 1) | |
did_assignments_change = tf.reduce_any(tf.not_equal(best_centroids, | |
cluster_assignments)) | |
def bucket_mean(data, bucket_ids, num_buckets): | |
total = tf.unsorted_segment_sum(data, bucket_ids, num_buckets) | |
count = tf.unsorted_segment_sum(tf.ones_like(data), bucket_ids, num_buckets) | |
return total / count | |
means = bucket_mean(points, best_centroids, K) | |
# Do not write to the assigned clusters variable until after | |
# computing whether the assignments have changed - hence with_dependencies | |
with tf.control_dependencies([did_assignments_change]): | |
do_updates = tf.group( | |
centroids.assign(means), | |
cluster_assignments.assign(best_centroids)) | |
init = tf.initialize_all_variables() | |
sess = tf.Session() | |
sess.run(init) | |
changed = True | |
iters = 0 | |
while changed and iters < MAX_ITERS: | |
iters += 1 | |
[changed, _] = sess.run([did_assignments_change, do_updates]) | |
[centers, assignments] = sess.run([centroids, cluster_assignments]) | |
end = time.time() | |
print ("Found in %.2f seconds" % (end-start)), iters, "iterations" | |
print "Centroids:" | |
print centers | |
print "Cluster assignments:", assignments |
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For text clustering first of all convert your dataset into vector using TfidfVectorizer and then apply any clustering algo.
For more deep use https://github.com/nfmcclure/tensorflow_cookbook/tree/master/07_Natural_Language_Processing