Type: Package
Title: Resampling Based Yield Stability Analyses
Version: 1.0.0
Author: Jixiang Wu
Maintainer: Jixiang Wu <jixiang.wu@sdstate.edu>
Description: Several yield stability analyses are mentioned in this package: variation and regression based yield stability analyses. Resampling techniques are integrated with these stability analyses. The function stab.mean() provides the genotypic means and ranks including their corresponding confidence intervals. The function stab.var() provides the genotypic variances over environments including their corresponding confidence intervals. The function stab.fw() is an extended method from the Finlay-Wilkinson method (1963). This method can include several other factors that might impact yield stability. Resampling technique is integrated into this method. A few missing data points or unbalanced data are allowed too. The function stab.fw.check() is an extended method from the Finlay-Wilkinson method (1963). The yield stability is evaluated via common check line(s). Resampling technique is integrated.
License: GPL-2
Encoding: UTF-8
LazyData: true
RoxygenNote: 7.1.1
Depends: R(≥ 4.0.0)
NeedsCompilation: no
Packaged: 2021-10-22 18:07:26 UTC; Jixiang.Wu
Repository: CRAN
Date/Publication: 2021-10-26 14:30:02 UTC

Maize yield trial data

Description

Maize yield trial data

Usage

maize

Format

An object of class data.frame with 260 rows and 4 columns.

References

Fan X.M., Kang M.S., Chen H.M., Zhang Y.D., Tan J., Xu C.X. (2007) Yield stability of maize hybrids evaluated in multi-environment trials in Yunnan, China. Agronomy Journal.99:220-228

Examples

str(maize)

F-W Regression Based Yield Stability Analysis

Description

F-W Regression Based Yield Stability Analysis

Usage

stab.fw(y, Gen, Env, times, Rep, X = NULL, alpha = NULL)

Arguments

y

A vector of yield data

Gen

A vector of Genotypes

Env

A vector of Environments

times

Replication number for resampling

Rep

Replication included or not included

X

Independent variables matrix or vector

alpha

Preset alpha value

Value

A list of yield stability results

References

Finlay, K.W., G.N. Wilkinson 1963. The analysis of adaptation in a plant breeding programme. Australian Journal of Agricultural Research 14: 742-754.

Wu, J., K. Glover, W. Berzonsky, 2012. Statistical tests for stability analysis with resampling techniques. 25th Conference of Applied Statistics in Agriculture. p88-108. April 29-May 01, 2012. Manhattan, KS

Wu, J., K. Glover, and N. Mueller 2014. Check based stability analysis method and its application to winter wheat variety trials," Conference on Applied Statistics in Agriculture. https://doi.org/10.4148/2475-7772.1006

Examples

require(genstab)
data(maize)
#names(maize)
Geno=as.vector(maize$Cultivar)
Env=paste(maize$Location,maize$Year,sep=":")
y=maize$Yld
res=stab.fw(y,Gen=Geno,Env=Env,times=10,Rep=TRUE)
res
##end

Check-based yield stability analysis

Description

Check-based yield stability analysis

Usage

stab.fw.check(y, Gen, Env, times, check, Rep, X = NULL, alpha = NULL)

Arguments

y

A response varible vector used for stability analysis

Gen

A vector of genotypes.

Env

A vector of environments.

times

Times of resampling used for stability analysis.

check

One or more checks used for stability analysis.

Rep

An argument with replication: Rep=TRUE or with replication: Rep=FALSE

X

A vector or matrix of other predictable variables. Default is NULL.

alpha

A nominal probability values used for statistical tests. Default is NULL, 0.05

Value

A list of yield stability results

References

Finlay, K.W., G.N. Wilkinson 1963. The analysis of adaptation in a plant breeding programme. Australian Journal of Agricultural Research 14: 742-754.

Wu, J., K. Glover, W. Berzonsky, 2012. Statistical tests for stability analysis with resampling techniques. 25th Conference of Applied Statistics in Agriculture. p88-108. April 29-May 01, 2012. Manhattan, KS

Wu, J., K. Glover, and N. Mueller 2014. Check based stability analysis method and its application to winter wheat variety trials," Conference on Applied Statistics in Agriculture. P102-114. https://doi.org/10.4148/2475-7772.1006

Examples

data(maize)
#names(maize)
Geno=as.vector(maize$Cultivar)
Env=paste(maize$Location,maize$Year,sep=":")
y=maize$Yld
res=stab.fw.check(y,Gen=Geno,Env=Env,times=10,check=c("Hai He"),Rep=FALSE)
res

Group means and ranks with resampling

Description

Group mean and rank calculation with two resampling techniques:permuation and bootstraping

Usage

stab.mean(Y, class, cls2 = NULL, resample, times = NULL, alpha = NULL)

Arguments

Y

A matrix including One or more traits

class

A vector of the first factor for calculating variance. For example, a vector of genotypes.

cls2

A vector of the second factor used within-group bootstraping for variance. It can be default

resample

Resampling technique option. resample="Boot" is for bootstrapping. resample="Perm" is for permutation.

times

Number of resampling used. The default number is 1000.

alpha

A nomimal probability used for statistical test. The default value is 0.05.

Value

A list of variances and confidence intervals for genotypes or environments

Author(s)

Jixiang Wu <jixiang.wu@sdstate.edu>

References

Finlay, K.W., G.N. Wilkinson 1963. The analysis of adaptation in a plant breeding programme. Australian Journal of Agricultural Research 14: 742-754.

Wu, J., K. Glover, W. Berzonsky, 2012. Statistical tests for stability analysis with resampling techniques. 25th Conference of Applied Statistics in Agriculture. p88-108. April 29- May 01, 2012. Manhattan, KS

Examples

data(maize)
#names(maize)
Geno=as.vector(maize$Cultivar)
Env=paste(maize$Location,maize$Year,sep=":")
y=maize$Yld
res=stab.mean(y,class=Geno,cls2=Env,resample="Boot",times=100)
res
res=stab.mean(y,class=Geno,resample="Perm",times=100)
res

Group variances with resampling

Description

Group variance calculation with two resampling techniques:permuation and bootstraping

Usage

stab.var(Y, class, cls2 = NULL, resample, times = NULL, alpha = NULL)

Arguments

Y

A matrix including One or more traits

class

A vector of the first factor for calculating variance. For example, a vector of genotypes.

cls2

A vector of the second factor used within-group bootstraping for variance. It can be default

resample

Resampling technique option. resample="Boot" is for bootstrapping. resample="Perm" is for permutation.

times

Number of resampling used. The default number is 1000.

alpha

A nomimal probability used for statistical test. The default value is 0.05.

Value

A list of variances and confidence intervals for genotypes or environments

Author(s)

Jixiang Wu <jixiang.wu@sdstate.edu>

References

Finlay, K.W., G.N. Wilkinson 1963. The analysis of adaptation in a plant breeding programme. Australian Journal of Agricultural Research 14: 742-754.

Wu, J., K. Glover, W. Berzonsky, 2012. Statistical tests for stability analysis with resampling techniques. 25th Conference of Applied Statistics in Agriculture. p88-108. April 29- May 01, 2012. Manhattan, KS

Examples

data(maize)
#names(maize)
Geno=as.vector(maize$Cultivar)
Env=paste(maize$Location,maize$Year,sep=":")
y=maize$Yld
res=stab.var(y,class=Geno,cls2=Env,resample="Boot",times=100)
res
res=stab.var(y,class=Geno,resample="Perm",times=100)
res