WheatPDA: Wheat virus in plant sap

In byandell/pda: Practial Data Analysis for Designed Experiments

Description

An agronomist (Katsiotis 1993) studied the effect of ploidy (number of copies of DNA chromosomes – humans have 2) on the yield in several species of alfalfa. The ploidy ranged from 2 to 8, with one to five species per ploidy. Within each species several matings (known as crosses) were arranged. Each mating produced about five accessions. Roughly 15 offspring from each accession were planted and later harvested to measure yield. This completely nested design has a mix of fixed effects (ploidy, species) and random effects (crosses, accessions, offspring).

Usage

data(WheatPDA)

Format

Wheat data frame with 192 observations on 8 variables.

[,1]	id	factor	bird identifier
[,2]	bact	factor	wheat or control
[,3]	temp	factor	room temperature
[,4]	inoc	factor	when innoculated
[,5]	bill	numeric	bill length
[,6]	leg	numeric	leg length
[,7]	code	factor	plot code
[,8]	trt	trt	bact*trt combination

Source

A Katsiotis, UW-Madison Agronomy Department (http://agronomy.wisc.edu)

References

Katsiotis A (1993) 'The determination and use of pollen grain size in four ploidy levels and the cytogenetics of tetraploid-octoploid hybrids in search of 2n gametes of Avena', PhD Dissertation, Department of Agronomy, University of Wisconsin-Madison.

Examples

data( WheatPDA )

# H:22.3 Wheat BLUEs and BLUPs
class( WheatPDA$ploidy ) = factor( WheatPDA$ploidy, ordered = FALSE )
WheatPDA$sp = interaction( WheatPDA$ploidy, WheatPDA$species)
WheatPDA$cr = interaction( WheatPDA$sp, WheatPDA$cross)
WheatPDA$ac = interaction( WheatPDA$cr, WheatPDA$accession)

## Not run: 
## this does not work properly: singular X'X matrix
library( lme4 )
Wheat.lme = lmer( tr1 ~ ploidy + sp + (1|cr) + (1|ac),
  data = WheatPDA, na.action = na.omit )
Wheat.lme = lmer( tr1 ~ ploidy + sp + (1|cross),
  data = WheatPDA, na.action = na.omit )

## End(Not run)

byandell/pda documentation built on May 13, 2019, 9:27 a.m.