iris2_nn.py

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import os

import numpy as np
import tensorflow as tf

tf.logging.set_verbosity(tf.logging.INFO)



# Data sets
IRIS_TRAINING = os.path.join(os.path.dirname(__file__), "iris_training.csv")
IRIS_TEST = os.path.join(os.path.dirname(__file__), "iris_test.csv")

def main(unused_argv):
    # Load datasets.
    training_set = tf.contrib.learn.datasets.base.load_csv_with_header(
        filename=IRIS_TRAINING, target_dtype=np.int, features_dtype=np.float32)
    test_set = tf.contrib.learn.datasets.base.load_csv_with_header(
        filename=IRIS_TEST, target_dtype=np.int, features_dtype=np.float32)

    # Specify that all features have real-value data
    feature_columns = [tf.contrib.layers.real_valued_column("", dimension=4)]

    validation_metrics = {
            "accuracy": tf.contrib.learn.MetricSpec(
                metric_fn=tf.contrib.metrics.streaming_accuracy,
                prediction_key=tf.contrib.learn.PredictionKey.CLASSES),

            "precision": tf.contrib.learn.MetricSpec(
                metric_fn=tf.contrib.metrics.streaming_precision,
                prediction_key=tf.contrib.learn.PredictionKey.CLASSES),

            "recall": tf.contrib.learn.MetricSpec(
                metric_fn=tf.contrib.metrics.streaming_recall,
                prediction_key=tf.contrib.learn.PredictionKey.CLASSES)
                
    }

    validation_monitor = tf.contrib.learn.monitors.ValidationMonitor(
                        test_set.data,
                        test_set.target,
                        every_n_steps=50,
                        metrics=validation_metrics,
                        early_stopping_metric="loss",
                        early_stopping_metric_minimize=True,
                        early_stopping_rounds=200)



    # Build 3 layer DNN with 10, 20, 10 units respectively.
    classifier = tf.contrib.learn.DNNClassifier(feature_columns=feature_columns,
                                                hidden_units=[10, 20, 10],
                                                n_classes=3,
                                                model_dir="/tmp/iris_model",
                                                config=tf.contrib.learn.RunConfig(save_checkpoints_secs=1))


    # Fit model.
    classifier.fit(x=training_set.data,
                   y=training_set.target,
                   steps=2000,
                   monitors=[validation_monitor])


    



    # Evaluate accuracy.
    accuracy_score = classifier.evaluate(x=test_set.data,
                                         y=test_set.target)["accuracy"]
    print('Accuracy: {0:f}'.format(accuracy_score))

    # Classify two new flower samples.
    new_samples = np.array(
        [[6.4, 3.2, 4.5, 1.5], [5.8, 3.1, 5.0, 1.7]], dtype=float)
    y = list(classifier.predict(new_samples, as_iterable=True))
    print('Predictions: {}'.format(str(y)))

if __name__ == "__main__":
  tf.app.run()