Wheat.dat

The data appears in Gilmour et al. [1995] and is from a field experiment designed to compare the
performance of 25 varieties of wheat. An analysis of it using asreml is presented by 
Butler et al. (2010, Sectoion 8.6), although they suggest that it is a barley experiment. It is used in <code><a rd-options="" href="/link/asremlPlus-package?package=asremlPlus&version=2.0-9" data-mini-rdoc="asremlPlus::asremlPlus-package">asremlPlus-package</a></code> as an executable example of the use of the <code>asremlPlus</code> to analyse a data set.The experiment was conducted at Slate Hall Farm, UK, in
1976 and was designed as a balanced lattice square with 6 replicates laid out in a 10 $x$ 15 rectangular
grid. The columns in the data frame are: Rep, Row, Column, WithinColPairs, Variety, yield.
The response variable is the grain yield.

datasets

Assists in automating the testing of terms in mixed models when 'asreml' is used
to fit the models. The content falls into the following natural groupings: (i) Data, (ii) Object
manipulation functions, (iii) Model modification functions, (iv) Model testing functions,
(v) Model diagnostics functions, (vi) Prediction production and presentation functions,
(vii) Response transformation functions, and (viii) Miscellaneous functions. A history of the
fitting of a sequence of models is kept in a data frame. Procedures are available for choosing
models that conform to the hierarchy or marginality principle and for displaying predictions
for significant terms in tables and graphs. The package 'asreml' provides a computationally
efficient algorithm for fitting mixed models using Residual Maximum Likelihood. It can be
purchased from 'VSNi' <http://www.vsni.co.uk/> as 'asreml-R', who will supply a zip file for
local installation/updating.

Chris Brien

asremlPlus

Augments the Use of 'Asreml' in Fitting Mixed Models

Wheat.dat function

A data.frame containing 150 observations of 6 variables.

Format

Butler, D. G., et al. (2010). Analysis of Mixed Models 
 for S language environments: ASReml-R reference manual. 
 Brisbane, DPI Publications. Gilmour, A. R., et al. (1995) Average Information REML: An efficient algorithm for 
 variance parameter estimation in linear mixed models. Biometrics, 
 51, 1440-1450.

Wheat.dat: Data for an experiment to investigate 25 varieties of wheat

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