import os
import pandas as pd
import numpy as np

# location will help to open files in the same directory as the py-script
__location__ = os.path.realpath(
    os.path.join(os.getcwd(), os.path.dirname(__file__)))

df = pd.read_csv(os.path.join(__location__, 'vl3-standardfehler.csv'))

# Dataframe
print(df)

print(df.sum())

sums = df.sum()
print('Summierte Häufigkeit: ', sums['freq'])


# Calculate Mean, respecting frequencies
rowSum = 0
for index, row in df.iterrows():
    rowSum = rowSum + row.x * row.freq
mean = rowSum / sums.freq
print("mean: ", mean)

# Geschätzte Populationsvarianz, unter Beachtung der Häufigkeiten
# Sample Variance: ^σ² = (1 / n - 1) * Σ(freq*(x - mean)²)
variancePart1 = (1 / (sums.freq - 1))
summeQuadrierteAbweichungen = 0
for index, row in df.iterrows():    
    summeQuadrierteAbweichungen = summeQuadrierteAbweichungen + (row.freq * (row.x - mean)**2)
    print(row['x'], row['freq'], 'summe²abweichungen: ', summeQuadrierteAbweichungen)
variance = variancePart1 * summeQuadrierteAbweichungen
print("pop variance: ", variance)

# √(^σ²)
standardDev = variance**(1/2) # √n = n^1/2
print("pop Standardabweichung: ", standardDev) 

# √(ŝd / freq)
standardfehler = standardDev / sums.freq**(1/2) # √n = n^1/2
print("Standardfehler des Mittelwerts: ", standardfehler) 











# "Bonus":

# Mittelwertsverteilung bei 2 Würfeln
print()
import random
i=0
sum=0
# Augen: (0,1,)2,3,4,5,6,7,8,9,10,11,12 Häufigkeitsliste:
freqList = [0,0,0,0,0,0,0,0,0,0,0,0,0] 
while i < 1000:    
    tempSum = 0
    wuerfel1 = random.randrange(1,7) # 1. Würfel {1,2,3,4,5,6}  
    wuerfel2 = random.randrange(1,7) # 2. Würfel {1,2,3,4,5,6}
    tempSum = tempSum + wuerfel1 + wuerfel2
    if tempSum == 2:
        freqList[2] = freqList[2] + 1
    elif tempSum == 3:
        freqList[3] = freqList[3] + 1
    elif tempSum == 4:
        freqList[4] = freqList[4] + 1
    elif tempSum == 5:
        freqList[5] = freqList[5] + 1
    elif tempSum == 6:
        freqList[6] = freqList[6] + 1
    elif tempSum == 7:
        freqList[7] = freqList[7] + 1
    elif tempSum == 8:
        freqList[8] = freqList[8] + 1
    elif tempSum == 9:
        freqList[9] = freqList[9] + 1
    elif tempSum == 10:
        freqList[10] = freqList[10] + 1
    elif tempSum == 11:
        freqList[11] = freqList[11] + 1
    elif tempSum == 12:
        freqList[12] = freqList[12] + 1        
    sum = sum + tempSum
    i = i+1
print("Mittelwert bei 2 Würfeln: ", sum / 1000)
print(freqList)