np.random.random 使用法

numpy.random.random

numpy.random. random ( size=None )

Return random floats in the half-open interval [0.0, 1.0).

Results are from the “continuous uniform” distribution over thestated interval. To sample multiplythe output of random_sample by (b-a) and add a:

(b - a) * random_sample() + a

Parameters:	size : int or tuple of ints, optional Output shape. If the given shape is, e.g., (m, n, k), thenm * n * k samples are drawn. Default is None, in which case asingle value is returned.
Returns:	out : float or ndarray of floats Array of random floats of shape size (unless size=None, in whichcase a single float is returned).

Examples

>>> np.random.random_sample()#返回一个随机数
0.47108547995356098
>>> type(np.random.random_sample())

>>> np.random.random_sample((5,))#一次返回五个随机数
array([ 0.30220482,  0.86820401,  0.1654503 ,  0.11659149,  0.54323428])

Three-by-two array of random numbers from [-5, 0):

>>> 5 * np.random.random_sample((3, 2)) - 5#一次返回一个随机数矩阵
array([[-3.99149989, -0.52338984],
       [-2.99091858, -0.79479508],
       [-1.23204345, -1.75224494]])