Keith Hair

This post might seem of little importance to some but today I was thinking back to my high school days and (vaguely) remember the 4 quadrants of a Cartesian coordinate plane discussed in class. Depending on the positive or negative sign of a Point's X and Y value, that point in the Cartesian coordinate plane will be located in one of these 4 quadrants.

Quadrant 1 = (+,+)
Quadrant 2 = (-,+)
Quadrant 3 = (-,-)
Quadrant 4 = (-,+)

My interest in this post is about the positive or negative sign of what the Cosine, Sine, and Tangent functions return for the same angle...the angle from one Point to another Point. The sign of these 3 Math functions are different also whenever a Point is located in one of the 4 quadrants.

Quadrant 1 = +Sine,+Cosine,+Tangent
Quadrant 2 = +Sine,-Cosine,-Tangent
Quadrant 3 = -Sine,-Cosine,+Tangent
Quadrant 4 = -Sine,+Cosine,-Tangent

Personally I don't think the order or name of the quadrants are important, as long as you keep them consistent with the coordinate system. For my usage, I order my quadrants "1,2,3,4" clockwise since ActionScript's radians values go clockwise.

I feel this will become useful sometime in the future for me when dealing with angles of Points and determining their positions relative to each other.
In a future situation I might not be given X and Y information, but may only have angle data instead. Seeing the difference of signs from the Cosign, Sine, Tangent output of the angle value will be helpful clues.

So some things come back to haunt you, if they are the ghosts of my math teachers, I will surely pay attention in class this time .

Since you are visiting, I will take this chance to say Happy New Year to you.
I am writing this on the event horizon of a new year. 2009 taught me that each day is a gift and we are not promised a tomorrow. Yes, this sounds so cliché but it is something a lot of us can relate to. That's pretty much all I have to say right now, so have a safe happy time...and a awesome HAPPY NEW YEAR!

-- Keith H --

If everyone got a turn, would you take your turn the same as the others or be different?

I've seen lots of really great knobs, dials, and gauge components. The intended way a person would build their app to use one would most likely be varied . That makes each of these kinds of controls  special because its difficult to make a control that fits a very broad range of functionality/look-n-feel, and probably why I have yet to see "one knob to rule them all".   Sliders, and Buttons are pretty straight forward, but not the "Knob" type of control.

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