"""
This file implements a class for a Linear function,
very similar to the Quadratic class of exercise 7.5.
There are two versions; one using a tuple to
represent the coefficients and one using two float
variables (commented out code).
The point is to illustrate that if all
such internal data are accessed through functions
such as get_coefficients, instead of being accessed
directly, the users of the class will not be affected
of a change in internal data structure.
"""

from numpy import linspace

class Linear:
  #class for linear functions f(x) = ax+b
  def __init__(self,a,b):
    #self.a = a
    #self.b = b
    self.coeff = (a,b)

  def value(self,x):
    a,b = self.coeff
    #a = self.a; b = self.b
    return a*x+ b

  def table(self,n,L,R):
    x_values = linspace(L,R,n)
    for x in x_values:
      print(x,value(x))

  def root(self):
    return -self.coeff[1]/self.coeff[0]
    #return -self.b/self.a

  def get_coefficients(self):
      return self.coeff
      #return self.a,self.b


line1 = Linear(1,0)
print(line1.root())
print(line1.get_coefficients())