Ancestral relation: Difference between revisions
en>TricksterWolf |
en>AnomieBOT m Dating maintenance tags: {{Clarify}} |
||
Line 1: | Line 1: | ||
In | In [[statistics]], '''best linear unbiased prediction''' ('''BLUP''') is used in linear [[mixed model]]s for the estimation of [[random effects model|random effects]]. BLUP was derived by [[Charles Roy Henderson]] in 1950 but the term "best linear unbiased predictor" (or "prediction") seems not to have been used until 1962.<ref name=Robinson>{{cite journal | ||
| last=Robinson |first=G.K. | |||
| year = 1991 | |||
| title = That BLUP is a Good Thing: The Estimation of Random Effects | |||
| journal = [[Statistical Science]] | |||
| volume = 6 | issue = 1 | pages = 15–32 | |||
| doi = 10.1214/ss/1177011926 | |||
| mr=1108815 | |||
| zbl=0955.62500 | |||
| jstor=2245695 | |||
}} | |||
</ref> "Best linear unbiased predictions" (BLUPs) of random effects are similar to best linear unbiased estimates (BLUEs) (see [[Gauss–Markov theorem]]) of fixed effects. The distinction arises because it is conventional to talk about ''estimating'' fixed effects but ''predicting'' random effects, but the two terms are otherwise equivalent. (This is a bit strange since the random effects have already been "realized" − they already exist. The use of the term "prediction" may be because in the field of animal breeding in which Henderson worked, the random effects were usually genetic merit, which could be used to predict the quality of offspring (Robinson<ref name=Robinson/> page 28). However, the equations for the "fixed" effects and for the random effects are different. | |||
In practice, it is often the case that the parameters associated with the random effect(s) term(s) are unknown; these parameters are the variances of the random effects and residuals. Typically the parameters are estimated and plugged into the predictor, leading to the [[Empirical Best Linear Unbiased Predictor]] (EBLUP). Notice that by simply plugging in the estimated parameter into the predictor, additional variability is unaccounted for, leading to overly optimistic prediction variances for the EBLUP. | |||
Best linear unbiased predictions are similar to [[empirical Bayes]] estimates of random effects in linear mixed models, except that in the latter case, where weights depend on unknown values of components of variance, these unknown variances are replaced by sample-based estimates. | |||
==Example== | |||
Suppose that the model for observations {''Y''<sub>''j''</sub>; ''j'' = 1, ..., ''n''} is written as | |||
:<math>Y_j= \mu + x_j^T\beta +\xi_j + \varepsilon_j, \, </math> | |||
where ''ξ<sub>j</sub>'' and ''ε<sub>j</sub>'' represent the random effect and observation error for observation ''j'', and suppose they are uncorrelated and have known variances ''σ<sub>ξ</sub>''<sup>2</sup> and ''σ<sub>ε</sub>''<sup>2</sup>, respectively. Further, ''x<sub>j</sub>'' is a vector of [[dependent and independent variables|independent variables]] for the ''j''th observation and ''β'' is a vector of regression parameters. The BLUP problem of providing an estimate of the observation-error-free value for the ''k''th observation, | |||
:<math>\tilde{Y_k}= \mu + x_k^T\beta +\xi_k ,</math> | |||
can be formulated as requiring that the coefficients of a linear predictor, defined as | |||
:<math>\widehat{Y_k}= \sum_{j=1}^n c_{j,k} Y_j ,</math> | |||
should be chosen so as to minimise the variance of the prediction error, | |||
:<math>V= \operatorname{Var}(\tilde{Y_k}- \widehat{Y_k}), </math> | |||
subject to the condition that the predictor is unbiased, | |||
:<math>\operatorname{E}(\tilde{Y_k}- \widehat{Y_k})=0 . </math> | |||
In contrast to the case of [[Best linear unbiased estimator|best linear unbiased estimation]], the "quantity to be estimated", <math>\tilde{Y_k}</math>, not only has a contribution from a random element but one of the observed quantities, specifically <math>Y_k</math> which contributes to <math>\widehat{Y_k}</math>, also has a contribution from this same random element. | |||
==See also== | |||
*[[Minimum mean square error]] | |||
==Tutorials== | |||
* [http://www.extension.org/pages/61006/the-solcap-tomato-phenotypic-data:-estimating-heritability-and-blups-for-traits#.Ui4zjWRgYXc Estimating BLUPs and Heritability Using R] | |||
* [http://www.extension.org/pages/68019/genomic-relationships-and-gblup Genomic Relationships and GBLUP] | |||
* [http://www.extension.org/pages/66590/rrblup-package-in-r-for-genomewide-selection Ridge Regression, rrBLUP for Genome-Wide Selection] | |||
==References== | |||
<references /> | |||
* {{cite journal | |||
|last=Henderson |first=C.R. |authorlink=Charles Roy Henderson | |||
|year=1975 | |||
|title=Best linear unbiased estimation and prediction under a selection model | |||
|journal=[[Biometrics (journal)|Biometrics]] | |||
|volume=31 |issue=2 |pages=423–447 | |||
|doi=10.2307/2529430 |pmid=1174616 | |||
|jstor=2529430 | |||
}} | |||
*Xu-Qing Liu, Jian-Ying Rong, Xiu-Ying Liu (2008). "Best linear unbiased prediction for linear combinations in general mixed linear models", Journal of Multivariate Analysis, 99 (8),1503–1517. {{doi|10.1016/j.jmva.2008.01.004}}. | |||
[[Category:Statistical methods]] | |||
[[Category:Estimation theory]] |
Revision as of 12:01, 17 September 2013
In statistics, best linear unbiased prediction (BLUP) is used in linear mixed models for the estimation of random effects. BLUP was derived by Charles Roy Henderson in 1950 but the term "best linear unbiased predictor" (or "prediction") seems not to have been used until 1962.[1] "Best linear unbiased predictions" (BLUPs) of random effects are similar to best linear unbiased estimates (BLUEs) (see Gauss–Markov theorem) of fixed effects. The distinction arises because it is conventional to talk about estimating fixed effects but predicting random effects, but the two terms are otherwise equivalent. (This is a bit strange since the random effects have already been "realized" − they already exist. The use of the term "prediction" may be because in the field of animal breeding in which Henderson worked, the random effects were usually genetic merit, which could be used to predict the quality of offspring (Robinson[1] page 28). However, the equations for the "fixed" effects and for the random effects are different.
In practice, it is often the case that the parameters associated with the random effect(s) term(s) are unknown; these parameters are the variances of the random effects and residuals. Typically the parameters are estimated and plugged into the predictor, leading to the Empirical Best Linear Unbiased Predictor (EBLUP). Notice that by simply plugging in the estimated parameter into the predictor, additional variability is unaccounted for, leading to overly optimistic prediction variances for the EBLUP.
Best linear unbiased predictions are similar to empirical Bayes estimates of random effects in linear mixed models, except that in the latter case, where weights depend on unknown values of components of variance, these unknown variances are replaced by sample-based estimates.
Example
Suppose that the model for observations {Yj; j = 1, ..., n} is written as
where ξj and εj represent the random effect and observation error for observation j, and suppose they are uncorrelated and have known variances σξ2 and σε2, respectively. Further, xj is a vector of independent variables for the jth observation and β is a vector of regression parameters. The BLUP problem of providing an estimate of the observation-error-free value for the kth observation,
can be formulated as requiring that the coefficients of a linear predictor, defined as
should be chosen so as to minimise the variance of the prediction error,
subject to the condition that the predictor is unbiased,
In contrast to the case of best linear unbiased estimation, the "quantity to be estimated", , not only has a contribution from a random element but one of the observed quantities, specifically which contributes to , also has a contribution from this same random element.
See also
Tutorials
- Estimating BLUPs and Heritability Using R
- Genomic Relationships and GBLUP
- Ridge Regression, rrBLUP for Genome-Wide Selection
References
- ↑ 1.0 1.1 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting
In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang
Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules
Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.
A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running
The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more
There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
- One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting
In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang
Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules
Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.
A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running
The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more
There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang - Xu-Qing Liu, Jian-Ying Rong, Xiu-Ying Liu (2008). "Best linear unbiased prediction for linear combinations in general mixed linear models", Journal of Multivariate Analysis, 99 (8),1503–1517. 21 year-old Glazier James Grippo from Edam, enjoys hang gliding, industrial property developers in singapore developers in singapore and camping. Finds the entire world an motivating place we have spent 4 months at Alejandro de Humboldt National Park..