def get_poly_1_deg(points, values):
sum_points = sum(points)
sum_points_2 = sum([point**2 for point in points])
sum_values = sum(values)
sum_v_p = sum([values[i] * points[i] for i in range(0, len(points))])
a = Matrix(2)
a.matrix = [[len(points), sum_points], [sum_points, sum_points_2]]
b = Vector(2)
b.vector = [sum_values, sum_v_p]
l, u, p = lup(a)
coefficients = lup_solve(l, u, p, b).vector
return parse_expr(f'{coefficients[0]} + {coefficients[1]} * x')
def get_poly_2_deg(points, values):
sum_points = sum(points)
sum_points_2 = sum([point**2 for point in points])
sum_points_3 = sum([point**3 for point in points])
sum_points_4 = sum([point**4 for point in points])
sum_values = sum(values)
sum_v_p = sum([values[i] * points[i] for i in range(0, len(points))])
sum_v_p2 = sum([values[i] * points[i]**2 for i in range(0, len(points))])
a = Matrix(3)
a.matrix = [[len(points), sum_points, sum_points_2],
[sum_points, sum_points_2, sum_points_3],
[sum_points_2, sum_points_3, sum_points_4]]
b = Vector(3)
b.vector = [sum_values, sum_v_p, sum_v_p2]
l, u, p = lup(a)
coefficients = lup_solve(l, u, p, b).vector
return parse_expr(
f'{coefficients[0]} + {coefficients[1]} * x + {coefficients[2]} * x ** 2'
)