Various python code to do Fibonacci related computations

sicp_1_13_pyfib.py

#!/usr/bin/python

# This is the python script I used to generate
# the table that illustrates my rambling answer
# to SICP exercise 1.13

import math

# Golden ratio and conjugate
phi = (1 + math.sqrt( 5 ) ) / 2
psi = (1 - math.sqrt( 5 ) ) / 2

# Linear recursive fib
def fib( n ):
    if n == 0 : return 0
    if n == 1 : return 1
    return fib( n - 1 ) + fib( n - 2 )

# approximation by golden ration
def goldfib( n ):
    return ( phi**n ) / math.sqrt( 5 )

# approximation of diff by psi
def psiroot( n ):
    return abs( ( psi**n ) / math.sqrt( 5 ) )

# closed form fib
def closed( n ):
    return ( (phi**n - psi**n) / math.sqrt( 5 ))

# chuck out an HTML table
def drawtable():
    n = 0
    while n < 20:
        print "<tr><td>\(",n,"\)</td>", \
            "<td>\(",fib(n),"\)</td>", \
            "<td>\(",goldfib(n),"\)</td>", \
            "<td>\(",closed(n),"\)</td>", \
            "<td>\(",psiroot(n),"\)</td></tr>"
        n = n + 1
		
drawtable();

Used to generate the table of results that supports the solution to SICP exercise 1.13 at http://www.enigmaticape.com/blog/sicp-exercise-1-13/