Re: please solve
- To: mathgroup at smc.vnet.net
- Subject: [mg52998] Re: please solve
- From: rcmcll at yahoo.com
- Date: Sun, 19 Dec 2004 06:14:43 -0500 (EST)
- References: <cprk0m$r87$1@smc.vnet.net><cpuh1i$gui$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Maybe I should define t. t is just time 1,2,3..,n and t^2 is 1,4,9,...n^2 like that. I didn't think about singularity as this is a simple regression problem that works when one uses actual values. I'm trying to get simple formulas for beta instead of the usual ones.Sorry about that. Maybe I can take usual formulas and try to get a simple solution thru that. Thanks for all the effort Bob Robert M. Mazo wrote: > On Thu, 16 Dec 2004 09:20:22 +0000 (UTC), rcmcll at yahoo.com wrote: > > >Greetings: > > > >Could someone please solve this symbolically? > >This is just the ols formula for beta-hat but I need a symbolic > >solution for this special case. > > > >b = inv(x'x)x'y > > > >where > > > >x = 1 t t^2 > >1 t t^2 > >1 t t^2 > > > > > >and simplify simplify simplify!! > > > >Thanks, > > > >Bob > > If I understand the notation, x is a matrix. Yes? If so, x is > singular and doesn't have an inverse. Hence neither does x'x, so the > problem has no solution. Or, better put, the problem is ill posed. > > A dsifferent Bob
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