Google Web Services for Free

Dave Winer recently broke the news that Google will soon introduce a “Google Web Services”,  a competitor to Amazon Web Services. This isn’t much of a shock to anyone. The extra bit that is somewhat of a surprise  is the price: free. He then explains that the reason it will be free is that they can pay for it in the reduced cost of integrating new acquisitions into their infrastructures which would become, effectively zero.

I don’t agree with that. At least I don’t think that is the main reason. I think it’s just the same old business model – basic service is free, premium is paid. The same model you see in Google Apps and a lot of other business on the web.

The basic service will be limited, in terms of traffic and/or storage (file and DB) etc. This will be the most widely used by startups. The premium service will just be the same pricing model amazon – pay as you go, the only different is that you don’t start paying at zero usage but rather at a higher threshold. When a startup becomes successful its needs will grow exponentially. They will be using more than the maximum allowed for free, and they’ll need to pay. But that’s alright because now that they are successful they can afford it. And the 1% or so that will be successful will have subsidized everyone that didn’t make it and still give Google a nice profit. Let’s not forget that Google’s infrastructure is already here and even tens of thousands of failed ventures won’t make a dent in it. Successful ventures will generate enough cash to upgrade that same infrastructure. Specially as the cost of hardware continues to drop.

Off course I’m sure people at Google also thought of the acquisition factor. Past acquisitions have taken a lot of time to be integrated. I think it took something like a year for writely to become “Google Docs“. That’s a very long time on the web.

Combine the free GWS with the powerful web development frameworks like Ruby on Rails that allow single individuals to create useful applications quickly and the new marketting oppurtunities that the web2.0 has created and the cost of trying won’t be measured in millions, thousands or even hundreds of dollars. It will be measured in terms of hours – the hours you “wasted” trying. And that, in many cases, won’t even be “time wasted” but rather “experience gained”.

It’s a brave new world indeed.

JabberLogBot

JabberLogBot is a jabber bot that records messages sent to it in a database.

The idea came from Nuno Dantas who wanted a jabber bot to record quick notes. He talked about it at a Prt.Sc dinner last Wennesday.

There’s also a simple PHP file in there that displays the data. That file is currently just for show as it is rather “plain”.

UPDATED: added a screenshot of the web viewer.

iPhone SDK now includes Interface Builder

The second beta version of the iPhone SDK is now available and includes Interface Builder, a powerful tool that allows you to visually build your interface and makes creating a UI as simple as drag and drop.

Screenshots:

Download at iPhone Dev Center

iHuman iForgot

Evernote Invites

I have 6 evernote (previously mentioned here) invites up for grabs. If you’re interested, drop a comment with your email.

Kickboxing Cup – K1 Rules – Coliseu do Porto

21h00, Saturday, March 29

Duration: 2h30min
Prices:
Plateia  – 30,00€
Tribuna – 25,00€
Camarotes 1a – 25,00€
Frisas  – 22,50€
Galeria/Geral  – 15,0

More Info @ Coliseu do Porto
www.kickboxingcup.com.pt

Numerical Methods and Python

I finally decided to take the Numerical Methods (MNUM) course. It turns out it’s a lot more fun than I thought. There is programming involved but you can chose to use whatever language you want. This is yet another nice excuse for me to use Python instead of C++ or Java. Last semester I was able to use Python to implement the game logic for Software Application Laboratory (LAS), which is mostly an OpenGL course with IPC via sockets thrown into the mix, and to write an article on dynamic languages (focusing mostly on Python) for Software Engineering (ESOF).

But back to this semester, 3 classes into the semester and the teacher is already said something like “I’m going to learn python now. I didn’t believe when I heard someone saying it was the best language in the world, but now I see there might be some truth to that claim”. That and I suspect his next laptop might be a macbook but that’s another story.

There are a few things that make Python great for Numerical Methods. In my opinion, Python’s clear, easy to understand, syntax is the most important one.It makes algorithms easier to implement. The syntax ends up being very close to language neutral pseudocode available in numerical methods books. Also Python’s datatypes as well as those provided by other libraries can be very useful.

The following code implements the stuff in chapter 2 (determining zeros) of the course. The methods implemented are Bisection, Rope and Newton. The function returns both the solution and the number of iterations necessary to get to that solution.

UPDATE: forgot the book - Numerical Methods in Engineering with Python

Appendix A – mnum2.py

from math import log

def bisect(f, a, b, e):
	""" Determines zero between a and b using Bisection. """
	n = 0
	fa = f(a)
	if fa == 0.0: return (a, n)
	fb = f(b)
	if fb == 0.0: return (b, n)

	while (abs(a-b) > e):
		c = 0.5*(a+b)
		fc = f(c)

		if fc == 0.0: return (c, n)
		n = n + 1
		if fb*fc < 0.0:
			a = c
			fa = fc

		else:
			b = c
			fb = fc

	if fa < fb:
		return (a, n)
	else:
		return (b, n)

def rope(f, a, b, e):
	""" Determines zero between a and b using the Rope methode. """
	n = 0
	fa = f(a)
	if fa == 0.0: return (a, n)
	fb = f(b)
	if fb == 0.0: return (b, n)

	while (abs(a-b) > e):
		c = (a*fb - b*fa) / (fb - fa)
		fc = f(c)
		if fc == 0.0: return (c, n)
		n = n + 1
		if fb*fc < 0:
			a = c
			fa = fc

		else:
			b = c
			fb = fc

	if fa < fb:
		return (a, n)
	else:
		return (b, n)

# Note: must verify that for the function f and guess c
#		the method will _converge_.
def newton(f, df, c, t):
	""" Determines zero between a and b using Newton """
	n = 0
	fc = f(c)
	if fc == 0.0: return (c, n)

	while (True):
		fc = f(c)
		dfc = df(c)
		if dfc == 0:
			print "dfc is 0"
			return (0, -1)

		dc = -fc/dfc

		c = c + dc
		n = n + 1
		if abs(dc) < t: return (c, n)

##Tests
#def f(x): return -log(x)+4.0
#def df(x): return -1.0/x
#x= bisect(f, 1, 70, 0.00000001)
#print x
#x = rope(f, 1, 70, 0.00000001)
#print x
#x = newton(f, df, 0.1, 0.0001)
#print x

Mathemagic featuring Arthur Benjamin

TED: Arthur Benjamin: Lightning calculation and other “Mathemagic”

Also see Youtube Mathemagic.

Min and Max – An explanation

Ok, from the comments on the previous post it seems people are NOT “getting it”. This is NOT a “problem”, this is funny.

So I guess people don’t know what the functions min() and max() do or are just confusing them

max([...]) - this function usually takes a list of numbers and returns the highest number in the list.

e.g.

if x belongs to [0,20] then y = max(x, 18) => y belongs to [18-20]

max(20,18) = 20
max(19, 18) = 19
max(10, 18) = 18

min([...]) - this function usually takes a list of numbers and returns the lowest number in the list.

e.g.

if x belongs to [0,20] then y = min(x, 18) => y belongs to [0-18]

min(20,18) = 18       [<- fixed thanks Mind Booster Noori]
min(19, 18) = 18
min(10, 18) = 10

This means that according to the function the function displayed in my previous post, according to that function, ALL students grades will be between 18 and 20. That means if you have a freaking 0 in the exam and a 0 in the Assignment you’ll get an 18/20 (which is an excellent grade). i.e. THE MINIMUM grade is 18. It’s a simple mistake in the equation. What the page should say to be correct is

Nota Final = min(Nota do exame final+Nota do trabalho, 18)<- this would be the correct equation

And hell this was posted under “Entertainment”.

So the previous post wasn’t supposed to be about something “unfair” it was supposed to be about making fun of a simple mistake that under the circumstances really is funny.

FEUP Maximizing Student Grades For A Change

Or not. Someone got min() and max() confused:

Nota Final = max(Nota do exame final+Nota do trabalho, 18)

translation: Final Grade = max(Exam Grade + Assignment Grade, 18)
[Note: it’s 18/20 – 20 is the maximum grade possible)

Than again, maybe it’s not  a mistake. Perhaps the teacher really enjoys giving high grades in the 18-20 range. Now wouldn’t that be different…

 Link to the page

UPDATE: Read my next post for an explanation of why this is funny.