fit_a_line v2 api

demo/introduction/api_train_v2.py

+import paddle.v2 as paddle
+import paddle.v2.dataset.uci_housing as uci_housing
+
+
+def main():
+    # init
+    paddle.init(use_gpu=False, trainer_count=1)
+
+    # network config
+    x = paddle.layer.data(name='x', type=paddle.data_type.dense_vector(13))
+    y_predict = paddle.layer.fc(input=x,
+                                param_attr=paddle.attr.Param(name='w'),
+                                size=1,
+                                act=paddle.activation.Linear(),
+                                bias_attr=paddle.attr.Param(name='b'))
+    y = paddle.layer.data(name='y', type=paddle.data_type.dense_vector(1))
+    cost = paddle.layer.regression_cost(input=y_predict, label=y)
+
+    # create parameters
+    parameters = paddle.parameters.create(cost)
+
+    # create optimizer
+    optimizer = paddle.optimizer.Momentum(momentum=0)
+
+    trainer = paddle.trainer.SGD(cost=cost,
+                                 parameters=parameters,
+                                 update_equation=optimizer)
+
+    # event_handler to print training and testing info
+    def event_handler(event):
+        if isinstance(event, paddle.event.EndIteration):
+            if event.batch_id % 100 == 0:
+                print "Pass %d, Batch %d, Cost %f, %s" % (
+                    event.pass_id, event.batch_id, event.cost, event.metrics)
+
+        if isinstance(event, paddle.event.EndPass):
+            result = trainer.test(
+                reader=paddle.reader.batched(
+                    uci_housing.test(), batch_size=2),
+                reader_dict={'x': 0,
+                             'y': 1})
+            if event.pass_id % 10 == 0:
+                print "Test %d, Cost %f, %s" % (event.pass_id, event.cost,
+                                                result.metrics)
+
+    # training
+    trainer.train(
+        reader=paddle.reader.batched(
+            paddle.reader.shuffle(
+                uci_housing.train(), buf_size=500),
+            batch_size=2),
+        reader_dict={'x': 0,
+                     'y': 1},
+        event_handler=event_handler,
+        num_passes=30)
+
+
+if __name__ == '__main__':
+    main()

python/paddle/v2/dataset/__init__.py

 import mnist
+import uci_housing
 
-__all__ = ['mnist']
+__all__ = ['mnist', 'uci_housing']

python/paddle/v2/dataset/uci_housing.py

+# Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import numpy as np
+import os
+from common import download
+
+__all__ = ['train', 'test']
+
+URL = 'https://archive.ics.uci.edu/ml/machine-learning-databases/housing/housing.data'
+MD5 = 'd4accdce7a25600298819f8e28e8d593'
+feature_names = [
+    'CRIM', 'ZN', 'INDUS', 'CHAS', 'NOX', 'RM', 'AGE', 'DIS', 'RAD', 'TAX',
+    'PTRATIO', 'B', 'LSTAT'
+]
+
+UCI_TRAIN_DATA = None
+UCI_TEST_DATA = None
+
+
+def feature_range(maximums, minimums):
+    import matplotlib
+    matplotlib.use('Agg')
+    import matplotlib.pyplot as plt
+    fig, ax = plt.subplots()
+    feature_num = len(maximums)
+    ax.bar(range(feature_num), maximums - minimums, color='r', align='center')
+    ax.set_title('feature scale')
+    plt.xticks(range(feature_num), feature_names)
+    plt.xlim([-1, feature_num])
+    fig.set_figheight(6)
+    fig.set_figwidth(10)
+    if not os.path.exists('./image'):
+        os.makedirs('./image')
+    fig.savefig('image/ranges.png', dpi=48)
+    plt.close(fig)
+
+
+def load_data(filename, feature_num=14, ratio=0.8):
+    global UCI_TRAIN_DATA, UCI_TEST_DATA
+    if UCI_TRAIN_DATA is not None and UCI_TEST_DATA is not None:
+        return
+
+    data = np.fromfile(filename, sep=' ')
+    data = data.reshape(data.shape[0] / feature_num, feature_num)
+    maximums, minimums, avgs = data.max(axis=0), data.min(axis=0), data.sum(
+        axis=0) / data.shape[0]
+    feature_range(maximums[:-1], minimums[:-1])
+    for i in xrange(feature_num - 1):
+        data[:, i] = (data[:, i] - avgs[i]) / (maximums[i] - minimums[i])
+    offset = int(data.shape[0] * ratio)
+    UCI_TRAIN_DATA = data[:offset]
+    UCI_TEST_DATA = data[offset:]
+
+
+def train():
+    global UCI_TRAIN_DATA
+    load_data(download(URL, 'uci_housing', MD5))
+
+    def reader():
+        for d in UCI_TRAIN_DATA:
+            yield d[:-1], d[-1:]
+
+    return reader
+
+
+def test():
+    global UCI_TEST_DATA
+    load_data(download(URL, 'uci_housing', MD5))
+
+    def reader():
+        for d in UCI_TEST_DATA:
+            yield d[:-1], d[-1:]
+
+    return reader