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- Timestamp:
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Jan 26, 2011, 2:09:30 PM (14 years ago)
- Author:
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Víctor de Buen Remiro
- Comment:
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11 | 11 | [source:/tolp/OfficialTolArchiveNetwork/GrzLinModel/WgtReg.tol @WgtReg] |
12 | 12 | is the base to inherit weighted generalized linear regressions as poisson, |
13 | | binomial, logit, probit or any other, given just the scalar distribution |
14 | | function [[LatexEquation( F )]] and the corresponding density function |
15 | | [[LatexEquation( f )]]. In a weighted regression each row of input data |
16 | | has a distinct weight in the likelihood function. For example, it can be |
17 | | very usefull to handle with data extrated from an stratified sample. |
| 13 | binomial, normal or any other, given just the scalar link |
| 14 | function [[LatexEquation( g )]] and the density function [[LatexEquation( f )]]. |
| 15 | |
| 16 | For boolean and qualitative response outputs like logit or probit there is an |
| 17 | specialization on package [wiki:OfficialTolArchiveNetworkQltvRespModel QltvRespModel] |
| 18 | |
| 19 | In a weighted regression each row of input data has a distinct weight in the |
| 20 | likelihood function. For example, it can be very usefull to handle with data extrated |
| 21 | from an stratified sample. |
18 | 22 | |
19 | 23 | Let be |
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23 | 27 | * [[LatexEquation( \beta\in\mathbb{R}^{n} )]] the regression coefficients |
24 | 28 | * [[LatexEquation( \eta=X\beta\in\mathbb{R}^{n} )]] the linear prediction |
25 | | * [[LatexEquation( \eta=X\beta\in\mathbb{R}^{n} )]] the linear prediction |
26 | 29 | * [[LatexEquation( g )]] the link function |
27 | | * [[LatexEquation( f )]] the density fuciton of a distribution of the |
28 | | [http://en.wikipedia.org/wiki/Exponential_family exponential family] |
| 30 | * [[LatexEquation( f)]] the density function of a distribution of the |
| 31 | [http://en.wikipedia.org/wiki/Exponential_family exponential family] |
29 | 32 | |
30 | 33 | Then we purpose that the average of the output is the inverse of the link function |
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33 | 36 | [[LatexEquation( E\left[y\right]=\mu=g^{-1}\left(X\beta\right) )]] |
34 | 37 | |
| 38 | The density function becomes as a real valuated function of at least two parameters |
| 39 | |
| 40 | [[LatexEquation( f\left(y_{k};\mu_{k}\right) )]] |
| 41 | |
| 42 | the output [[LatexEquation( y_k )]] and the average |
| 43 | |
| 44 | [[LatexEquation( \mu_{k}=g^{-1}\left(\eta_{k}\right)=g^{-1}\left(x_{k}\beta\right) )]] |
| 45 | |
| 46 | for each row [[LatexEquation( k=1 \dots n)]]: |
| 47 | |
| 48 | If there are more unknown parameters about the density we will supose |
| 49 | |
| 50 | |
| 51 | === Weighted Poisson Regresion === |