spd_example

A balanced series of split plot experiments: two environments,
 four replications, two main plot levels and three subplot levels.

datasets

Pooled analysis of a series of designed experiments repeated over locations, seasons or years, where treatment-by-environment interaction is of primary interest. One design-specific function call performs environment-wise analysis of variance, formal testing of homogeneity of error variances, an optional variance-stabilising transformation, pooled analysis of variance with the correct error stratum for every effect, and multiple comparison of means. Five classical designs are supported: completely randomised ('PooledCRD()'), randomised block ('PooledRBD()'), Latin square ('PooledLSD()'), split plot ('PooledSPD()') and strip plot ('PooledStPD()'). Homogeneity of error variances is assessed by Bartlett's test computed on the environment-wise error mean squares as in Bartlett (1937) <doi:10.1098/rspa.1937.0109>, and by the median-centred Brown-Forsythe form of Levene's test <doi:10.1080/01621459.1974.10482955>, which is robust to non-normality. When variances are heterogeneous, Aitken's transformation (division of each observation by the square root of the error mean square of its own environment) may be applied, and treatment means are reported on both the transformed and the original scale. For split plot and strip plot designs every effect is tested against its proper error term, and mean separation uses the error mean square and degrees of freedom of the corresponding stratum. The statistical theory is given in Cochran and Cox (1957, ISBN:9780471162032), Gomez and Gomez (1984, ISBN:9780471870928), Dean et al. (2017) <doi:10.1007/978-3-319-52250-0> and Ruiz et al. (2024) <doi:10.1007/978-3-031-65575-3>.

Vinayaka 

CANE

Comprehensive Groups of Experiments Analysis for Numerous
Environments

 Vinayaka

T. Lakshmi Pathy

Gopalareddy Krishnappa

Shweta Kumari

P. Murali

P. Govindaraj

P. Rama Chandra Prasad

L.N. Vinaykumar

spd_example function

A data frame with 48 rows and 5 variables:<dl>
 <dt>Location</dt>
<dd>Factor with 2 levels, the environment.</dd> <dt>Replication</dt>
<dd>Factor with 4 levels.</dd> <dt>MainPlot</dt>
<dd>Factor with 2 levels, the main plot (whole plot) factor.</dd> <dt>SubPlot</dt>
<dd>Factor with 3 levels, the subplot factor.</dd> <dt>Yield</dt>
<dd>Numeric response.</dd>
</dl>

Format

Illustrative Split Plot Design Series — spd_example

A data frame with 48 rows and 5 variables:<dl>
 <dt>Location</dt>
<dd>Factor with 2 levels, the environment.</dd>

 <dt>Replication</dt>
<dd>Factor with 4 levels.</dd>

 <dt>MainPlot</dt>
<dd>Factor with 2 levels, the main plot (whole plot) factor.</dd>

 <dt>SubPlot</dt>
<dd>Factor with 3 levels, the subplot factor.</dd>

 <dt>Yield</dt>
<dd>Numeric response.</dd>


</dl>

Illustrative Split Plot Design Series

spd_example: Illustrative Split Plot Design Series

Description

Usage

Arguments

Format

Details

Examples