Type HalfNormal
Namespace tensorflow.contrib.distributions
Parent Distribution
Interfaces IHalfNormal
The Half Normal distribution with scale `scale`. #### Mathematical details The half normal is a transformation of a centered normal distribution.
If some random variable `X` has normal distribution,
```none
X ~ Normal(0.0, scale)
Y = |X|
```
Then `Y` will have half normal distribution. The probability density
function (pdf) is: ```none
pdf(x; scale, x > 0) = sqrt(2) / (scale * sqrt(pi)) *
exp(- 1/2 * (x / scale) ** 2)
)
```
Where `scale = sigma` is the standard deviation of the underlying normal
distribution. #### Examples Examples of initialization of one or a batch of distributions.
Show Example
import tensorflow_probability as tfp
tfd = tfp.distributions # Define a single scalar HalfNormal distribution.
dist = tfd.HalfNormal(scale=3.0) # Evaluate the cdf at 1, returning a scalar.
dist.cdf(1.) # Define a batch of two scalar valued HalfNormals.
# The first has scale 11.0, the second 22.0
dist = tfd.HalfNormal(scale=[11.0, 22.0]) # Evaluate the pdf of the first distribution on 1.0, and the second on 1.5,
# returning a length two tensor.
dist.prob([1.0, 1.5]) # Get 3 samples, returning a 3 x 2 tensor.
dist.sample([3])
Properties
Public properties
object allow_nan_stats get;
object allow_nan_stats_dyn get;
TensorShape batch_shape get;
object batch_shape_dyn get;
object dtype get;
object dtype_dyn get;
TensorShape event_shape get;
object event_shape_dyn get;
string name get;
object name_dyn get;
IDictionary<object, object> parameters get;
object parameters_dyn get;
object PythonObject get;
object reparameterization_type get;
object reparameterization_type_dyn get;
object scale get;
Distribution parameter for the scale.
object scale_dyn get;
Distribution parameter for the scale.