Polar Coordinate transformations in 3D

In 2d, converting a theta and
radius (in circular polar coordinates) into a cartesian X and Y, are performed via the following functions:

x=cos(theta)*r;
y=sin(theta)*r;

In 3d, a phi angle is added to the spherical polar coordinates and converting theta, phi, and radius into a X, Y, and Z.

If Z is the “height” of the point above the XY-plane, and phi is the
angle between the XY-plane and the vector formed by the line from the origin to (x,y,z), then the following functions can be used.

x = r * cos(theta) * cos(phi)
y = r * sin(theta) * cos(phi)

and

z = r * sin(phi)

Also, see http://cmldev.net/

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Podcasts are cool

It’s the second week of the winter pledge drive on NPR, so I’ve been listening to podcasts instead of the radio during the commute.

There are full college-level courses for free up on “iTunes U”. I’ve been listening to the lectures from some freshman astronomy classes by a professor at Ohio State. Very cool stuff.

It pays to be a late adopter sometimes.

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Make #21 is here

w00t! Makey goodness. I’m only a few pages in, but the Arduweeny looks fun.

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Comfy.

…but a bit odd

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For the creatively-minded

photomake

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fer flanging thangs

fer the jawb
fer the crib

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I will do science to it.

nuff said.

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hardware RNG

Seems like you should be able to pull truly random numbers out of a hardware circuit. Tune into the CMB or some other kind of noisy circuit, sample it, and voila, all the random you can eat.

hm.

Needs thought.

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I Love to Learn

The joy of taking a subject about which I know nothing and digging into it to learn what it’s about is much like opening Christmas presents to me. What’s inside is nice, but the anticipation and the unwrapping is what really gets me going.

I live in a world where compilers catch “stupid” mistakes (getting all the grammar and syntax correct), and I can concentrate on the more “interesting” ones (does this thing do what I want it to?). This leads, inevitably, to an iterative approach to problem-solving. Try something, see how it works, tweak it a little, try it again, et cetera.

Come to think of it, it’s probably my history with videogames that leads me to this sort of behavior. When I was young, I discovered that in a game, I could try daring and creative approaches, and if I failed, I was offered an opportunity to try again.

This is a powerful gift.

Of course one is going to make mistakes during the learning process. That’s what learning is. “Flunking” is not representative of the way life works. Which is not to say that one should just ignore grades and the “fancy book learning” offered in school. What I’m saying is that messing up while learning is fine, but if you’re actually learning through the process of failure and reattempt, then both the grades and the knowledge will come.

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360 controller as mouse

360 Controller as mouse

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