# -*- coding: utf-8 -*-
"""
Created on Sat Mar  7 10:41:51 2020

@author: Johan Rene van Dorp
"""

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

df = pd.read_csv('OldFaithFul.csv')
Durations = df["Duration (s)"]
WaitingTimes = df["Waiting Time (Min)"]

# Plotting Empirical Cumulative Distribution Functions

plt.rc('font', family='serif', size='10')
plt.figure(figsize=(10, 5))
ECDF_Figure = plt.figure()
ECDF_Figure.subplots_adjust(hspace=0.4, wspace=0.4)
off_set_x = 10

# Plotting the Empirical CDF of the Durations

n_d = len(Durations)
LB = 90
UB = 330
Durations.ordered = np.sort(Durations)
Durations.ordered = np.append(LB-off_set_x,Durations.ordered)
Durations.ordered = np.append(Durations.ordered,UB+off_set_x)
F = np.linspace(0,1,n_d)
F = np.append(0,F)
F = np.append(F,1)

x_lims = (LB-off_set_x,UB+off_set_x)
y_lims = (-0.05,1.1)
Panel = ECDF_Figure.add_subplot(1,2,1)
plt.step(Durations.ordered,F,lw = 1,color ='indianred')
plt.xlim(x_lims)
plt.ylim(y_lims)
plt.xlabel('Duration (in Sec)')
plt.ylabel('Empirical CDF $\hat{F}(d) = Pr(D \leq d)$')
plt.axvline(0, lw=2, ls = '-',color = 'lightgray',alpha=0.5)
plt.axhline(0, lw=2, ls = '-',color = 'lightgray',alpha=0.5)
plt.axhline(1, lw=2, ls = ':',color = 'lightgray',alpha=0.5)
text_str = 'n = '+str(n_d)
plt.text(160,0.9,text_str,color = 'red',size = 10)

# Plotting the Empirical CDF of the Waiting Times

LB = 40
UB = 100
n_w = len(WaitingTimes)
WaitingTimes.ordered = np.sort(WaitingTimes)
WaitingTimes.ordered = np.append(LB-off_set_x,WaitingTimes.ordered)
WaitingTimes.ordered = np.append(WaitingTimes.ordered,UB+off_set_x)
F = np.linspace(0,1,n_d)
F = np.append(0,F)
F = np.append(F,1)

x_lims = (LB-off_set_x,UB+off_set_x)
y_lims = (-0.05,1.1)
Panel = ECDF_Figure.add_subplot(1,2,2)
plt.step(WaitingTimes.ordered,F,lw = 1,color ='skyblue')
plt.xlim(x_lims)
plt.ylim(y_lims)
plt.xlabel('Waiting Times (in Min)')
plt.ylabel('Empirical CDF $\hat{F}(w) = Pr(W \leq w)$')
plt.axvline(0, lw=2, ls = '-',color = 'lightgray',alpha=0.5)
plt.axhline(0, lw=2, ls = '-',color = 'lightgray',alpha=0.5)
plt.axhline(1, lw=2, ls = ':',color = 'lightgray',alpha=0.5)
text_str = 'n = '+str(n_w)
plt.text(55,0.9,text_str,color = 'red',size = 10)

ECDF_Figure.suptitle('Empirical CDFs Old Faithful Data',size='14')
plt.savefig('Old_Faithful_ECDF.png', dpi=1200)