#fibonacchossequence

[kenduring]

[mairag]

Fibonacci Sequence in Nature - Proof of a designer?

[adaj9]

Es increíble cómo las matemáticas nos rodean.

[rulo-zeepb-d-lash]

[jhr-python]

The Fibonacci sequence : Recursion: The Good; the Bad and the really kind of ugly

Theory:  The Fibonacci numbers  (series  or sequence)  are the numbers in the integer sequence: 0,1,1,2,3,5,8,12,21..  which can be defined more  compactly  by:

with seed values

This, along with the factorial ,  are often used as a way to introduce people to concept of recursion; which I assume the reader is already familiar with. Further more; one can also talk about adaptive methods when dealing the most resource effective ways  of calculating it.

The big idea:  Here is the standard recursion implementation of calculating a fibonacci number 

if n is less than 2 ( i.e. 0 or 1) return 1

else call the function again for the next two lowest values:  

Writing the code: 

https://gist.github.com/6324950

Why is this bad?  While to code is pretty straightforward to read and understand; the resource usage here is bad due to the inherent repeated calculation.  This function is asymptotically O(2n).

To make this better; the fix is to somehow keep track of the values that are already  calculated instead of determining them as need. I will show the two more popular methods in future write ups.

[emileesaurus]

fibonacchossequence replied to your post: … the thumbnail image for my birdflash tracked tag...

It flyfay, she was just desperate and asked sage to help her. i forgive her … it’s ust. :( but YEAH i was like WHAT TH E WAT

lollll no i know, i actually reblogged the thing it was from when i saw it earlier

IT'S GR8, SERIOUSLY

BUT IT'S STILL HILARIOUS (because i laugh at my own suffering)

[bentfire]

fibonacchossequence replied to your post

seriously, it’s fine - where are you? it’s like afternoon over here! Have you been up all night?? ;-; haha.

it's 2:19pm where I am, and I actually went to bed early and slept fairly well so idk what my problem is but I fell asleep while screencapping gl:tas and I just wanna curl up in my bed and sleeeeeeeeeeep :( /holy run-on sentence, batman!