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Index › Suggestions & Bugs › Website,  Documentation,  Book Bugs › Position IS a vector (PVector math documentation)
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Position IS a vector (PVector math documentation) (Read 1848 times)
drtimo
Position IS a vector (PVector math documentation)
Nov 21st, 2009, 9:31pm  
I just wanted to comment that you have no need to make apologies about position being described as a vector since position IS a vector.  Check out any physics book.  It is defined as the vector that points from the origin of the coordinate system (your choice to define it, and the upper left corner in the case of processing) to the location described by the position.  Without the position being a vector, velocity doesn't even make sense (nor acceleration) since they are both related to the change of position over time.  

Anyway, I just wanted to mention this not for the sake of instruction, but just so that the documentation can be corrected when whoever is in charge of it has the time to do so.  By the way, I'm rather new to processing, and am loving it!

Dr T
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d.rifkin
Re: Position IS a vector (PVector math documentation)
Reply #1 - Nov 22nd, 2009, 3:12am  
The apology probably has something to do with the homogenous coordinate system often used in computer graphics.  In that coordinate system, positions (vertices) must be considered points, rather than vectors, for certain matrix transformations (e.g., translation) to work as expected.

You are correct though, the documentation seems to be discussing position in a physics context.
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Daniel Shiffman
Re: Position IS a vector (PVector math documentation)
Reply #2 - Jan 7th, 2010, 6:55am  
Thanks for this comment. I'm currently working on a PVector tutorial for the site which addresses this point exactly.    When this is posted I should update the PVector reference page as well.
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