tensorflow add操作的一个现象

a = tf.placeholder("float", [None, 3])b = tf.placeholder("float", [3])c = tf.add(a,b)with tf.Session() as sess:  print sess.run(c, feed_dict={a: [[1,1,1]], b: [2, 2, 2]})  print sess.run(c, feed_dict={a: [[1,1,1],[2,2,2]],b:[2,2,2]})

结果
[[ 3. 3. 3.]]
[[ 3. 3. 3.]
[ 4. 4. 4.]]