jax.scipy.special.logit¶

jax.scipy.special.logit = <jax.custom_derivatives.custom_jvp object>[source]¶

Logit ufunc for ndarrays.

LAX-backend implementation of logit(). Original docstring below.

logit(x, /, out=None, *, where=True, casting=’same_kind’, order=’K’, dtype=None, subok=True[, signature, extobj])

logit(x)

The logit function is defined as logit(p) = log(p/(1-p)). Note that logit(0) = -inf, logit(1) = inf, and logit(p) for p<0 or p>1 yields nan.

Parameters: x (ndarray) – The ndarray to apply logit to element-wise.
Returns: out – An ndarray of the same shape as x. Its entries are logit of the corresponding entry of x.
Return type: ndarray

See also

expit

Notes

As a ufunc logit takes a number of optional keyword arguments. For more information see ufuncs

New in version 0.10.0.

Examples

>>> from scipy.special import logit, expit

>>> logit([0, 0.25, 0.5, 0.75, 1])
array([       -inf, -1.09861229,  0.        ,  1.09861229,         inf])

expit is the inverse of logit:

>>> expit(logit([0.1, 0.75, 0.999]))
array([ 0.1  ,  0.75 ,  0.999])

Plot logit(x) for x in [0, 1]:

>>> import matplotlib.pyplot as plt
>>> x = np.linspace(0, 1, 501)
>>> y = logit(x)
>>> plt.plot(x, y)
>>> plt.grid()
>>> plt.ylim(-6, 6)
>>> plt.xlabel('x')
>>> plt.title('logit(x)')
>>> plt.show()