1_linear_regression.py

import tensorflow as tf
import numpy as np

trX = np.linspace(-1, 1, 101)
trY = 2 * trX + np.random.randn(*trX.shape) * 0.33 # create a y value which is approximately linear but with some random noise

X = tf.placeholder("float") # create symbolic variables
Y = tf.placeholder("float")


def model(X, w):
    return tf.mul(X, w) # lr is just X*w so this model line is pretty simple


w = tf.Variable(0.0, name="weights") # create a shared variable (like theano.shared) for the weight matrix
y_model = model(X, w)

cost = (tf.pow(Y-y_model, 2)) # use sqr error for cost function

train_op = tf.train.GradientDescentOptimizer(0.01).minimize(cost) # construct an optimizer to minimize cost and fit line to my data

sess = tf.Session()
init = tf.initialize_all_variables() # you need to initialize variables (in this case just variable W)
sess.run(init)

for i in range(100):
    for (x, y) in zip(trX, trY): 
        sess.run(train_op, feed_dict={X: x, Y: y})

print(sess.run(w))  # something around 2