#  Demonstration code for Scientific Computing class,
#  http://www.math.nyu.edu/faculty/goodman/teaching/SciComp2022/
#  IntegrandClass.py
#  uses Python 3 and Numpy
#  Demonstrate a software package, with IntegrandDemo.py
#  and IntegrationPackage.py

import numpy as np

class Integrand:
   """define a polynomial function.
   """
   
   def __init__( self, deg, coeffs):
      """Remember the degree of the polynomial and its coefficients"""
      self.deg = deg
      if ( deg != ( coeffs.size - 1 )):
         print("YOU IDIOT")
         print(str(coeffs))
      else:
         local_coeffs = np.array(coeffs)  # construct a new array with  the
                                          # given coefficients, to avoid
                                          # implicit dependency.
         self.coeffs = local_coeffs

   def f( self, x):           # Evaluate the polynomial at x
   
      xk  = 1.                # will be x^k
      sum = 0.                # will be f(x)
      deg    = self.deg       # "remember" the information that...
      coeffs = self.coeffs    # ... defines the polynomial
      for k in range(deg+1):  # there are n+1 terms in a degree n poly
         sum = sum + coeffs[k]*xk
         xk  = xk * x
      return sum  # but it should be.