scipy.stats.uniform — SciPy v1.15.2 Manual (original) (raw)
scipy.stats.uniform = <scipy.stats._continuous_distns.uniform_gen object>[source]#
A uniform continuous random variable.
In the standard form, the distribution is uniform on [0, 1]
. Using the parameters loc
and scale
, one obtains the uniform distribution on [loc, loc + scale]
.
As an instance of the rv_continuous class, uniform object inherits from it a collection of generic methods (see below for the full list), and completes them with details specific for this particular distribution.
Examples
import numpy as np from scipy.stats import uniform import matplotlib.pyplot as plt fig, ax = plt.subplots(1, 1)
Calculate the first four moments:
mean, var, skew, kurt = uniform.stats(moments='mvsk')
Display the probability density function (pdf
):
x = np.linspace(uniform.ppf(0.01), ... uniform.ppf(0.99), 100) ax.plot(x, uniform.pdf(x), ... 'r-', lw=5, alpha=0.6, label='uniform pdf')
Alternatively, the distribution object can be called (as a function) to fix the shape, location and scale parameters. This returns a “frozen” RV object holding the given parameters fixed.
Freeze the distribution and display the frozen pdf
:
rv = uniform() ax.plot(x, rv.pdf(x), 'k-', lw=2, label='frozen pdf')
Check accuracy of cdf
and ppf
:
vals = uniform.ppf([0.001, 0.5, 0.999]) np.allclose([0.001, 0.5, 0.999], uniform.cdf(vals)) True
Generate random numbers:
r = uniform.rvs(size=1000)
And compare the histogram:
ax.hist(r, density=True, bins='auto', histtype='stepfilled', alpha=0.2) ax.set_xlim([x[0], x[-1]]) ax.legend(loc='best', frameon=False) plt.show()
Methods
rvs(loc=0, scale=1, size=1, random_state=None) | Random variates. |
---|---|
pdf(x, loc=0, scale=1) | Probability density function. |
logpdf(x, loc=0, scale=1) | Log of the probability density function. |
cdf(x, loc=0, scale=1) | Cumulative distribution function. |
logcdf(x, loc=0, scale=1) | Log of the cumulative distribution function. |
sf(x, loc=0, scale=1) | Survival function (also defined as 1 - cdf, but sf is sometimes more accurate). |
logsf(x, loc=0, scale=1) | Log of the survival function. |
ppf(q, loc=0, scale=1) | Percent point function (inverse of cdf — percentiles). |
isf(q, loc=0, scale=1) | Inverse survival function (inverse of sf). |
moment(order, loc=0, scale=1) | Non-central moment of the specified order. |
stats(loc=0, scale=1, moments=’mv’) | Mean(‘m’), variance(‘v’), skew(‘s’), and/or kurtosis(‘k’). |
entropy(loc=0, scale=1) | (Differential) entropy of the RV. |
fit(data) | Parameter estimates for generic data. See scipy.stats.rv_continuous.fit for detailed documentation of the keyword arguments. |
expect(func, args=(), loc=0, scale=1, lb=None, ub=None, conditional=False, **kwds) | Expected value of a function (of one argument) with respect to the distribution. |
median(loc=0, scale=1) | Median of the distribution. |
mean(loc=0, scale=1) | Mean of the distribution. |
var(loc=0, scale=1) | Variance of the distribution. |
std(loc=0, scale=1) | Standard deviation of the distribution. |
interval(confidence, loc=0, scale=1) | Confidence interval with equal areas around the median. |