mindspore.nn.probability.distribution.Logistic
- class mindspore.nn.probability.distribution.Logistic(loc=None, scale=None, seed=None, dtype=mstype.float32, name='Logistic')[source]
Logistic distribution.
- Parameters
loc (int, float, list, numpy.ndarray, Tensor) – The location of the Logistic distribution. Default: None.
scale (int, float, list, numpy.ndarray, Tensor) – The scale of the Logistic distribution. Default: None.
seed (int) – The seed used in sampling. The global seed is used if it is None. Default: None.
dtype (mindspore.dtype) – The type of the event samples. Default: mstype.float32.
name (str) – The name of the distribution. Default: ‘Logistic’.
- Supported Platforms:
Ascend
GPU
Note
scale must be greater than zero. dist_spec_args are loc and scale. dtype must be a float type because Logistic distributions are continuous.
Examples
>>> import mindspore >>> import mindspore.nn as nn >>> import mindspore.nn.probability.distribution as msd >>> from mindspore import Tensor >>> # To initialize a Logistic distribution of loc 3.0 and scale 4.0. >>> l1 = msd.Logistic(3.0, 4.0, dtype=mindspore.float32) >>> # A Logistic distribution can be initialized without arguments. >>> # In this case, `loc` and `scale` must be passed in through arguments. >>> l2 = msd.Logistic(dtype=mindspore.float32) >>> >>> # Here are some tensors used below for testing >>> value = Tensor([1.0, 2.0, 3.0], dtype=mindspore.float32) >>> loc_a = Tensor([2.0], dtype=mindspore.float32) >>> scale_a = Tensor([2.0, 2.0, 2.0], dtype=mindspore.float32) >>> loc_b = Tensor([1.0], dtype=mindspore.float32) >>> scale_b = Tensor([1.0, 1.5, 2.0], dtype=mindspore.float32) >>> >>> # Private interfaces of probability functions corresponding to public interfaces, including >>> # `prob`, `log_prob`, `cdf`, `log_cdf`, `survival_function`, and `log_survival`, >>> # have the same arguments as follows. >>> # Args: >>> # value (Tensor): the value to be evaluated. >>> # loc (Tensor): the location of the distribution. Default: self.loc. >>> # scale (Tensor): the scale of the distribution. Default: self.scale. >>> # Examples of `prob`. >>> # Similar calls can be made to other probability functions >>> # by replacing 'prob' by the name of the function >>> ans = l1.prob(value) >>> print(ans.shape) (3,) >>> # Evaluate with respect to distribution b. >>> ans = l1.prob(value, loc_b, scale_b) >>> print(ans.shape) (3,) >>> # `loc` and `scale` must be passed in during function calls >>> ans = l1.prob(value, loc_a, scale_a) >>> print(ans.shape) (3,) >>> # Functions `mean`, `mode`, `sd`, `var`, and `entropy` have the same arguments. >>> # Args: >>> # loc (Tensor): the location of the distribution. Default: self.loc. >>> # scale (Tensor): the scale of the distribution. Default: self.scale. >>> # Example of `mean`. `mode`, `sd`, `var`, and `entropy` are similar. >>> ans = l1.mean() >>> print(ans.shape) () >>> ans = l1.mean(loc_b, scale_b) >>> print(ans.shape) (3,) >>> # `loc` and `scale` must be passed in during function calls. >>> ans = l1.mean(loc_a, scale_a) >>> print(ans.shape) (3,) >>> # Examples of `sample`. >>> # Args: >>> # shape (tuple): the shape of the sample. Default: () >>> # loc (Tensor): the location of the distribution. Default: self.loc. >>> # scale (Tensor): the scale of the distribution. Default: self.scale. >>> ans = l1.sample() >>> print(ans.shape) () >>> ans = l1.sample((2,3)) >>> print(ans.shape) (2, 3) >>> ans = l1.sample((2,3), loc_b, scale_b) >>> print(ans.shape) (2, 3, 3) >>> ans = l1.sample((2,3), loc_a, scale_a) >>> print(ans.shape) (2, 3, 3)
- property loc
Return the location of the distribution after casting to dtype.
- property scale
Return the scale of the distribution after casting to dtype.