在classifier.fit
函数中将步数从2000更改为1会返回相同的精度结果。我希望准确度结果不同,有人可以告诉我为什么吗?
代码来自Tensorflow示例:
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import os
import numpy as np
import tensorflow as tf
# 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)]
# 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")
# Fit model.
classifier.fit(x=training_set.data,
y=training_set.target,
steps=1)
# 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()
答案 0 :(得分:0)
原因很简单:您已经定义了分类器的model_dir
参数。这是文档所说的内容:
model_dir
:保存模型参数,图表等的目录。这可以 也可用于将检查点从目录加载到估算器中 继续训练以前保存的模型。
当您多次运行模型时,它不会从头开始学习,而是从"/tmp/iris_model"
中获取以前的权重。
如果您想进行公平的测试,请删除此参数,您将看到小步骤的精确度下降,高步骤的精度下降。