使用 TensorFlow 计算多元回归 [英] Calculating Multivariate regression using TensorFlow

问题描述

我正在尝试在 tensorflow 中实现多元回归，其中我有 192 个具有 6 个特征和一个输出变量的示例.从我的模型中我得到一个矩阵 (192, 6) 而它应该是 (192, 1).有人知道我的代码有什么问题吗?我在下面提供了我的代码.

I am trying to implement a Multivariate regression in tensorflow where I have 192 examples with 6 features and one output variable. From my model I get a matrix (192, 6) while it should be (192, 1). Does anybody know what is wrong with my code? I provided my code below.

# Parameters
learning_rate = 0.0001
training_epochs = 50
display_step = 5

train_X = Data_ABX3[0:192, 0:6]
train_Y = Data_ABX3[0:192, [24]]


# placeholders for a tensor that will be always fed.
X = tf.placeholder('float', shape = [None, 6])
Y = tf.placeholder('float', shape = [None, 1])


# Training Data

n_samples = train_Y.shape[0]


# Set model weights
W = tf.cast(tf.Variable(rng.randn(1, 6), name="weight"), tf.float32)
b = tf.Variable(rng.randn(), name="bias")

# Construct a linear model
pred = tf.add(tf.multiply(X, W), b)

# Mean squared error
cost = tf.reduce_sum(tf.pow(pred-Y, 2))/(2*n_samples)
# Gradient descent
#  Note, minimize() knows to modify W and b because Variable objects are       trainable=True by default
optimizer = tf.train.GradientDescentOptimizer(learning_rate).minimize(cost)

# Accuracy
# #accuracy = tf.contrib.metrics.streaming_accuracy(Y, pred)

# Initialize the variables (i.e. assign their default value)
init = tf.global_variables_initializer()

# Start training
with tf.Session() as sess:

    # Run the initializer
    sess.run(init)

    # Fit all training data
    for epoch in range(training_epochs):
        #for (x, y) in zip(train_X, train_Y):
        sess.run(optimizer, feed_dict={X: train_X, Y: train_Y})

        # Display logs per epoch step
        if (epoch+1) % display_step == 0:
            c = sess.run(cost, feed_dict={X: train_X, Y:train_Y})
            print("Epoch:", '%04d' % (epoch+1), "cost=", "{:.9f}".format(c), \
                "W=", sess.run(W), "b=", sess.run(b))

    print("Optimization Finished!")
    #training_cost = 0
    #for (x, y) in zip(train_X, train_Y):
    #     tr_cost = sess.run(cost, feed_dict={X: x, Y: y})
    #     training_cost += tr_cost
    training_cost = sess.run(cost, feed_dict={X: train_X, Y: train_Y})
    print("Training cost=", training_cost, "W=", sess.run(W), "b=", sess.run(b), '\n')

    # Graphic display
    plt.plot(train_Y, train_X * sess.run(W) + sess.run(b), label='Fitted line')
    plt.legend()
    plt.show()

推荐答案

请在您的 pred 中使用 tf.matmul 而不是 tf.multiply> 等式.tf.multiply 进行元素乘法，因此，它会生成一个与 train_X 维度相同的矩阵，而 tf.matmul 会做一个矩阵乘法并将根据实际的矩阵乘法规则生成结果矩阵.

Please use tf.matmul instead of tf.multiply in your pred equation. tf.multiply does a element wise multiplication hence, it will generate a matrix of same dimension as train_X, whereas tf.matmul will do a matrix multiplication and will generate the resultant matrix based on the actual matrix multiplication rule.

我不确定你的数据是什么.添加随机数据，然后更改代码以满足所有维度要求.如果你能帮助我实现你的意图，那将有助于更好地看待问题.

I am not sure what is your data. Adding random data and then changed code to meet all the dimension requirements. If you can help me with your intention, that will help in seeing the issue better.

编辑

import numpy as np
import tensorflow as tf
import matplotlib.pyplot as plt
# Parameters
learning_rate = 0.0001
training_epochs = 50
display_step = 5

Data_ABX3 = np.random.random((193, 8)).astype('f')

train_X = Data_ABX3[0:192, 0:6]
train_Y = Data_ABX3[0:192, [7]]


# placeholders for a tensor that will be always fed.
X = tf.placeholder('float32', shape = [None, 6])
Y = tf.placeholder('float32', shape = [None, 1])

# Training Data
n_samples = train_Y.shape[0]

# Set model weights
W = tf.cast(tf.Variable(np.random.randn(6, 1), name="weight"), tf.float32)
b = tf.Variable(np.random.randn(), name="bias")

mult_node = tf.matmul(X, W)
print(mult_node.shape)
# Construct a linear model
pred = tf.add(tf.matmul(X, W), b)

# Mean squared error
cost = tf.reduce_sum(tf.pow(pred-Y, 2))/(2*n_samples)
# Gradient descent
#  Note, minimize() knows to modify W and b because Variable objects are               trainable=True by default
optimizer = tf.train.GradientDescentOptimizer(learning_rate).minimize(cost)

# Accuracy
# #accuracy = tf.contrib.metrics.streaming_accuracy(Y, pred)

# Initialize the variables (i.e. assign their default value)
init = tf.global_variables_initializer()

# Start training
with tf.Session() as sess:

# Run the initializer
sess.run(init)

# Fit all training data
for epoch in range(training_epochs):
    #for (x, y) in zip(train_X, train_Y):
    sess.run(optimizer, feed_dict={X: train_X, Y: train_Y})

    # Display logs per epoch step
    if (epoch+1) % display_step == 0:
        c = sess.run(cost, feed_dict={X: train_X, Y:train_Y})
        print("Epoch:", '%04d' % (epoch+1), "cost=", "{:.9f}".format(c), \
            "W=", sess.run(W), "b=", sess.run(b))

print("Optimization Finished!")
#training_cost = 0
#for (x, y) in zip(train_X, train_Y):
#     tr_cost = sess.run(cost, feed_dict={X: x, Y: y})
#     training_cost += tr_cost
training_cost = sess.run(cost, feed_dict={X: train_X, Y: train_Y})
print("Training cost=", training_cost, "W=", sess.run(W), "b=", sess.run(b), '\n')

line = sess.run(tf.add(tf.matmul(train_X, W), b))
# Graphic display
plt.plot(train_Y, line, label='Fitted line')
plt.legend()
plt.show()`

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