Article View: comp.lang.pascal.borland
Article #31Re: 3d programming
From: Gregory Lo
Date: Tue, 20 Feb 1996 11:13
Date: Tue, 20 Feb 1996 11:13
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3448 bytes
In article <4g8b5i$irm@dfw.nkn.net>, TheAnalyst@Nfo.Org wrote: > Now where the hell do you get "any ordered pair" from the above definitions, or > should I dig out my 8th grade linear algebra book :( don't ask why I still have > it ): . > Just dug it out anyway. NOWHERE is there a definition or is "vector" even > listed. Let me guess. You didn't take math or computer science in university/college. I wouldn't really assume that 8th grade (junior high!!) linear algebra would discuss more advanced than the concept of variables. I don't even think you would cover polynomial functions. In fact, I wouldn't expect functions and relations to be covered. > Just did a little more research. Guess what. . . "Vector" is not considered a > part of "linear Algebra", it is a part of Physics and Calculus. So unless you > have an 8th grade education and that is where you stopped, your definition of > "vector" is "a quantity requiring both magnitude and direction to be defined". Considered by whom? 8th grade students? This is bullsh*t. True, a geometric vector may be a quantity requiring both magnitude and direction. However, in order to manipulate this within the framework of an n-dimensional vector space , you normally represent it as an n-tuple. Very simple examples Cartesian 1-dimensional: [2], [3], [-2], [-500], etc. Cartesian 2-dimensional: [2,4], [6,-3], [-12,64], etc. <-- this is your ordered pair Cartesian n-dimensional: [a1,a2,a3,...,an], etc <-- this is your n-tuple These cartesian vectors are made of the coefficients to a linear combination of vector components. In other words your vector w=[3,4] could be written as w=3i+4j In a cartesian coordinate system, these components are usually orthogonal, running along the coordinate axes. The coefficients may be real or complex, depending on the vector space. A point is implicitly a vector. It can be described as a displacement from a reference point. For instance, if your point p=(5,2), then it could be rewritten p=[0,0]+[5,2] A generic point can be decribed as a vector equation p = r + k (r1) or as a Cartesian equation A(kn) + .... + B(k2) + C(k1) + D = 0 These vectors could be represented as n-tuples describing polar coordinates, using n-1 angles and a length scalar. This is only covers certain kinds of vectors, and is a gross simplification. Eventually, you'll have the math to work with matrices and functions as special kinds of vectors.
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Path: arc1-ca.pugleaf.net!free1-slip204.tele.queensu.ca!user From: 3gl21@qlink.queensu.ca (Gregory Lo) Newsgroups: comp.lang.pascal.borland,comp.lang.pascal.mac,comp.lang.pascal.ansi-iso,comp.lang.pascal.misc,comp.sys.amiga.programmer,comp.graphics.algorithms,comp.os.ms-windows.programmer.graphics,comp.sys.amiga.graphics Subject: Re: 3d programming Date: Tue, 20 Feb 1996 05:05:14 -0608 Organization: Queen's University Message-ID: <3gl21-2002960505140001@free1-slip204.tele.queensu.ca> References: <4f3od9$2jg@zeus.tcp.co.uk> <jderrick-0502961551360001@slip037.csc.cuhk.hk> <3118310E.52F@psu.edu> <4fiuh2$qrj@fulton.cs.unc.edu> <311E38D7.71BC@psu.edu> <4frlln$lp5@dfw.nkn.net> <Pine.OSF.3.91.960214142740.20349A-100000@curtis.aa.washington.e <4g2vue$3s9@mckinley.cit.macalstr.edu> <4g8b5i$irm@dfw.nkn.net> Reply-To: 3gl21@qlink.queensu.ca NNTP-Posting-Host: free1-slip204.tele.queensu.ca X-Newsreader: Yet Another NewsWatcher 2.2.0b4