Model code and output for a comparison of methods for meta-analysis investigating covariance between genetic and environmental (CovGE) effects in phenotypic results

The data for the CovGE meta-analysis from the RCN-ECS project were published as dataset \"Metadata for studies from meta-analysis investigating covariance between genetic and environmental (CovGE) effects in phenotypic results (DOI: 10.26008/1912/bco-dmo.877414.1).\" However, this dataset contains a meta-analysis comparing our approach with the method described by Stamp and Hadfield (2020) in Ecology Letters.

The data tables in this dataset contain output of the model described in forthcoming results publication Albecker et al. (n.d.) \"Meta-analysis reveals patterns of cogradient and countergradient variation.\" This results publication used meta-analysis to measure CovGE and GxE across 354 phenotypes within 64 studies.

Katie Lotterhos, with input from the authors, created the \"Behavior_of_PL_metric.Rmd\" file which provides an in-depth comparison of the two measures and contains R code and rendered figures created with R-Markdown (.Rmd). Dr. Lotterhos documented code and interpretation to demonstrate similarities and contrasts among the two approaches (see Supplemental File \"Behavior_of_PL_metric.pdf\"). She also uses subsets of simulated data to demonstrate how the two approaches calculate CovGE or PL metric using the same data.

RCN-ECS项目中涉及遗传与环境协方差（CovGE）效应的元分析数据，以数据集“探究表型结果中遗传与环境协方差（CovGE）效应的元分析研究元数据（DOI: 10.26008/1912/bco-dmo.877414.1）”形式正式发布。不过，该数据集还包含一项元分析，用于对比本研究方法与Stamp和Hadfield于2020年在《生态学通讯（Ecology Letters）》中提出的研究方法。

本数据集的数据表包含即将发表的Albecker等人（未注日期）论文《元分析揭示协变与逆协变变异模式（Meta-analysis reveals patterns of cogradient and countergradient variation）》中所描述模型的输出结果。该研究通过元分析方法，对64项研究中的354个表型开展了CovGE与基因型-环境互作（GxE）的量化分析。

在作者们的协助下，Katie Lotterhos制作了“Behavior_of_PL_metric.Rmd”文件，该文件对两种量化方法进行了深入对比，其中包含R代码与通过R Markdown（.Rmd）渲染生成的可视化图表。Lotterhos博士对代码及解读过程进行了文档化处理，以阐明两种方法的异同（详见补充文件“Behavior_of_PL_metric.pdf”）。此外，她还利用模拟数据的子集，演示了两种方法如何基于同一数据计算CovGE与PL指标。