spacepy.toolbox.poisson_fit¶
- spacepy.toolbox.poisson_fit(data, initial=None, method='Powell')[source]¶
Fit a Poisson distribution to data using the method and initial guess provided.
- Parameters:
- dataarray-like
Data to fit a Poisson distribution to.
- initialint or None
initial guess for the fit, if None np.median(data) is used
- methodstr
method passed to scipy.optimize.minimize, default=’Powell’
- Returns:
- resultscipy.optimize.optimize.OptimizeResult
Resulting fit results from scipy.optimize, answer is result.x, user should likely round.
Examples
>>> import spacepy.toolbox as tb >>> from scipy.stats import poisson >>> import matplotlib.pyplot as plt >>> import numpy as np >>> data = poisson.rvs(20, size=1000) >>> res = tb.poisson_fit(data) >>> print(res.x) 19.718000038769095 >>> xvals = np.arange(0, np.max(data)+5) >>> plt.hist(data, bins=xvals, normed=True) >>> plt.plot(xvals, poisson.pmf(xvals, np.round(res.x)))