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Summer

I won’t be taking any other math classes this Summer (except 2 credit independent study), and the work I’ll be doing is bound to be highly personal. We’re talking, tricked out home site and portfolio, doing work with friends such as the relaunch of of Marjorie Bevis’ Marbled Fabrics, and perhaps the genesis of some sort of local peer-commerce/underground economy social networking site, which has been in conceptual stages among my friends.


Perfect number finder in python

In the interest of greater openness (sharing my inner life with the world and such), here is a bit of python I just wrote to find perfect numbers. After a few minutes of optimization, it is now quite fast and no longer brings OSX to its knees with memory-hungryness:

from math import *
def is_perfect(a):
	sum = 1 
	for i in xrange(2, floor(sqrt(a))):
		if a%i == 0:
			sum = sum + i + a/i
	if sqrt(a)%1 == 0: sum += sqrt(a)
	return sum == a

def find_perfect(limit):
	results = []
	for i in xrange(1, limit):
		j=2**i*(2**(i+1)-1)
		if is_perfect(j):
			results.append(j)

Nokia 770 Hackathon Notes

Poky linux 3.1.

  • supports 770 with image
  • doesn’t come with wifi driver, power mgmt

Wireless

Chipset is cx3110 with bitbake recipe in poky. How to build this in an image?

  • power-management

Sprint: Evil? Ya.

The other day Sprint turned my phone off. Their Terms Of Service give a $150 penalty for terminating service in the 2nd year of your contract. Any change you make to your plan resets the contract (even changing the number of minutes) .

I want out.

I want cheap, flexible VoIP service with SIP. SIP interoperates with everything: other networks, hardware phones, softphones. For example, there is a version of Gizmo, a crossplatform SIP client, available for Nokia’s WLAN equiped 770 handheld.

Why not Skype? Skype uses a proprietary protocol which doesn’t interoperate with much of anything (although it does have software for pocketpc). I have experienced artifacts and dropouts when talking on Skype, even over a fast cable connection. SIP softphones seem to have cleaner audio, possibly due to the automatic codec negotiation inherent in the protocol.

SIPPhone, the service which backs the Gizmo client, has free SIP-to-SIP calling and cheap international POTS and mobile minutes. There is no monthly service charge, unless you lease a local phone number for $12 dollars every 3 months so that you can receive calls from regular phones.

I was impressed with SIPPhone’s slick account management site: buy minutes, modify your user profile, add people to your phone book, even dial your phone via the web interface. I could definitely see using the service with a web tablet like the 770.

Poppa Sprint breathing down your neck? Get SIP!


Intro to Sage

Sage is…

  • A general purpose symbolic computer algebra system (CAS) like Mathematica, Maple, Magma, etc.
  • Designed to be accessible and useful right away for people with some math background.
  • Accessed through your browser.
  • Powerful, as we shall see…

Why Sage? We have Mathematica…

  • Cost.

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