我有一个计算概率的函数,如下所示:
def multinormpdf(x, mu, var): # calculate probability of multi Gaussian distribution
k = len(x)
det = np.linalg.det(var)
inv = np.linalg.inv(var)
denominator = math.sqrt(((2*math.pi)**k)*det)
numerator = np.dot((x - mean).transpose(), inv)
numerator = np.dot(numerator, (x - mean))
numerator = math.exp(-0.5 * numerator)
return numerator/denominator
我有均值向量、协方差矩阵和 2D numpy 数组用于测试
mu = np.array([100, 105, 42]) # mean vector
var = np.array([[100, 124, 11], # covariance matrix
[124, 150, 44],
[11, 44, 130]])
arr = np.array([[42, 234, 124], # arr is 43923794 x 3 matrix
[123, 222, 112],
[42, 213, 11],
...(so many values about 40,000,000 rows),
[23, 55, 251]])
我必须计算每个值的概率,所以我使用了这个代码
for i in arr:
print(multinormpdf(i, mu, var)) # I already know mean_vector and variance_matrix
但是速度太慢了...
有没有更快的方法来计算概率?或者有什么方法可以像“批处理”一样一次计算测试 arr 的概率?
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