numpy求平均值的维度设定的例子

>>> a = np.array([[1, 2], [3, 4]]) >>> np.mean(a) # 将上面二维矩阵的每个元素相加除以元素个数（求平均数） 2.5 >>> np.mean(a, axis=0) # axis=0，计算所有子数组的平均值 array([ 2., 3.]) >>> np.mean(a, axis=1) # axis=1，对每一个子数组，计算它的平均值array([ 1.5, 3.5]) 

X = np.mean(last_layer_delta_of_all_input, axis=0)print 'X:', Xprint 'X_shape:', X.shapeprint 'own mean'X = np.zeros((10,1))for delta in last_layer_delta_of_all_input: X += deltaX /= 10print 'own X:', X