import pandas as pd
import numpy as np

data = pd.read_csv('PTC_LUT.csv', comment='#')

temp = data['Temperature']
resist = data['Resistance']

volt = 403.2
dissiFac = 0.0195
ambTemp = 45

powerLoss = -1
powerCreate = 0
i = 0

# Find the zone where the lines intersect
while powerCreate>powerLoss:
    powerLoss = (temp[i] - ambTemp)*dissiFac
    powerCreate = np.square(volt) / resist[i]
    i = i + 1

# put zone into points to solve for intersection
p1 = [i-1, (temp[i-1] - ambTemp)*dissiFac]
p2 = [i, (temp[i] - ambTemp)*dissiFac]

p3 = [i-1, np.square(volt) / resist[i-1]]
p4 = [i, np.square(volt) / resist[i]]

# Line 1 dy, dx and determinant
a11 = (p1[1] - p2[1])
a12 = (p2[0] - p1[0])
b1 = (p1[0]*p2[1] - p2[0]*p1[1])

# Line 2 dy, dx and determinant
a21 = (p3[1] - p4[1])
a22 = (p4[0] - p3[0])
b2 = (p3[0]*p4[1] - p4[0]*p3[1])

# Construction of the linear system
# coefficient matrix
A = np.array([[a11, a12],
              [a21, a22]])

# right hand side vector
b = -np.array([b1,
               b2])
# solve
try:
    intersection_point = np.linalg.solve(A,b)
    print('Intersection point detected at:', intersection_point)
    print('Result:')
    print('Temperature: ', intersection_point[1]/dissiFac+ambTemp)
    print('Resistance: ', np.square(volt)/intersection_point[1])
except np.linalg.LinAlgError:
    print('No single intersection point detected')