plm 模型“内部"- R 中的警告消息 [英] plm model "within" - Warning messages in R

问题描述

我在运行此 plm 模型时遇到问题:

i have a problem running this plm model:

我的数据是(示例):

    country=c(1,1,1,2,2,2,3,3,3)
    year=c(1,2,3,1,2,3,1,2,3)
    a=c(1,4,6,3,5,8,4,5,7)
    b=c(8,5,7,2,7,4,9,7,1)
    matrix=cbind(country, year, a, b)
    matrix=plm.data(matrix)

我运行以下回归:

    reg=plm(a~year+b, data=matrix, index=NULL, model="within")
    summary(reg)

并收到以下警告消息:[1]

and get following warning message:[1]

    Warning messages:
    1: In if (is.na(le)) { :
      the condition has length > 1 and only the first element will be used
    2: In if (is.na(le)) " __no length(.)__ " else if (give.length) { :
      the condition has length > 1 and only the first element will be used
    3: In if (le > 0) paste0("[1:", paste(le), "]") else "(0)" :
      the condition has length > 1 and only the first element will be used

怎么了?

推荐答案

这是因为 str 检查其对象的长度，而 plm 使用来自 plm 的扩展公式代码>公式包.现在，Formula:::length.Formula 返回一个向量而不是一个数字，这会导致警告，如 simon_icl 所述.虽然您自己可能不会调用 str，但您的 IDE(例如 RStudio)可能会使用它来显示工作区中对象的对象结构.

This is because str checks the length of its object, and plm uses extended formulas from the Formula package. Now, Formula:::length.Formula returns a vector rather than a number, which causes the warning, as explained by simon_icl. While you may not call str yourself, perhaps your IDE, say RStudio, may use it to show the object structure of objects in the workspace.

这篇关于plm 模型“内部"- R 中的警告消息的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！