def prep_energy_prices_contract(self, plot):
        #Bratford distribution parameters
        c = 1
        loc = self.cotract_price_range[0]
        scale = self.cotract_price_range[1] - self.cotract_price_range[0]

        price_vec = bradford.rvs(c, loc=loc, scale=scale, size=1000)
        if plot:
            fig, ax = plt.subplots(1, 1)
            ax.hist(price_vec, density=True, histtype='stepfilled', alpha=0.2)
            ax.legend(loc='best', frameon=False)
            plt.show()

        return price_vec
#Calculate a few first moments:
c = 0.299
mean, var, skew, kurt = bradford.stats(c, moments='mvsk')
#Display the probability density function (pdf):
x = np.linspace(bradford.ppf(0.01, c), bradford.ppf(0.99, c), 100)
ax.plot(x, bradford.pdf(x, c), 'r-', lw=5, alpha=0.6, label='bradford 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 = bradford(c)
ax.plot(x, rv.pdf(x), 'k-', lw=2, label='frozen pdf')
#Check accuracy of cdf and ppf:
vals = bradford.ppf([0.001, 0.5, 0.999], c)
np.allclose([0.001, 0.5, 0.999], bradford.cdf(vals, c))
True
#Generate random numbers:
r = bradford.rvs(c, size=1000)
#And compare the histogram:
ax.hist(r, density=True, histtype='stepfilled', alpha=0.2)
ax.legend(loc='best', frameon=False)
plt.show()

#burr Continuous distributions¶
from scipy.stats import burr
import matplotlib.pyplot as plt
import numpy as np

fig, ax = plt.subplots(1, 1)
#Calculate a few first moments:
c, d = 10.5, 4.3
mean, var, skew, kurt = burr.stats(c, d, moments='mvsk')
#Display the probability density function (pdf):