diff --git a/conversions/Newton_forward.py b/conversions/Newton_forward.py new file mode 100644 index 000000000000..490e0687f15f --- /dev/null +++ b/conversions/Newton_forward.py @@ -0,0 +1,57 @@ +# https://www.geeksforgeeks.org/newton-forward-backward-interpolation/ +from __future__ import annotations + +import math + + +# for calculating u value +def ucal(u: float, p: int) -> float: + """ + >>> ucal(1, 2) + 0 + >>> ucal(1.1, 2) + 0.11000000000000011 + >>> ucal(1.2, 2) + 0.23999999999999994 + """ + temp = u + for i in range(1, p): + temp = temp * (u - i) + return temp + + +def main() -> None: + n = int(input("enter the numbers of values: ")) + y: list[list[float]] = [] + for i in range(n): + y.append([]) + for i in range(n): + for j in range(n): + y[i].append(j) + y[i][j] = 0 + + print("enter the values of parameters in a list: ") + x = list(map(int, input().split())) + + print("enter the values of corresponding parameters: ") + for i in range(n): + y[i][0] = float(input()) + + value = int(input("enter the value to interpolate: ")) + u = (value - x[0]) / (x[1] - x[0]) + + # for calculating forward difference table + + for i in range(1, n): + for j in range(n - i): + y[j][i] = y[j + 1][i - 1] - y[j][i - 1] + + summ = y[0][0] + for i in range(1, n): + summ += (ucal(u, i) * y[0][i]) / math.factorial(i) + + print(f"the value at {value} is {summ}") + + +if __name__ == "__main__": + main()