如何在函数内使用lmer [英] How to use lmer inside a function

问题描述

我正在尝试编写一个函数，该函数收集脚本中经常使用的一些调用
我在示例中使用了lme4包的sleepstudy数据
这是我开始使用的功能(的简化版本):

I'm trying to write a function that collects some calls I use often in scripts
I use the sleepstudy data of the lme4 package in my examples
Here's (a simplified version of) the function I started with:

trimModel1 <- function(frm, df) {
  require(LMERConvenienceFunctions)
  require(lme4)

  lm<-lmer(frm,data=df)
  lm.trimmed = romr.fnc(lm, df)
  df = lm.trimmed$data
  # update initial model on trimmed data
  lm<-lmer(frm,data=df)
#   lm@call$formula<-frm
  mcp.fnc(lm)
  lm
}

当我像下面这样调用此函数时:

When I call this function like below:

(fm1<-trimModel1(Reaction ~ Days + (Days|Subject),sleepstudy))

输出的前三行如下所示:

The first three lines of the output look like this:

Linear mixed model fit by REML 
Formula: frm    
Data: df

如果我在控制台中调用了trimModel1函数的命令，则模型摘要的前三行如下所示:

If I had called the commands of the trimModel1 function in the console the first three lines of the summary of the model look like this:

Linear mixed model fit by REML 
Formula: Reaction ~ Days + (Days | Subject) 
   Data: sleepstudy 

差异是一个问题，因为使用lme4软件包的多个软件包都使用了公式和数据字段.例如，效果包使用了这些字段，而当我使用上面的trimModel1函数时，如下所示的命令将不起作用:

The difference is a problem because several packages that use the lme4 package make use of the formula and data fields. For instance the effects package uses these fields and a command like below will not work when I use the trimModel1 function above:

library(effects)
plot(allEffects(fm1))

我在stackoverflow和R讨论组中四处寻找解决方案，发现可以更改模型的公式字段.如果取消注释trimModel1函数中的lm@call$formula<-frm行，则摘要中的公式字段将正确显示.不幸的是，当我现在从effects包运行一个函数时，仍然出现错误:

I looked around on stackoverflow and R discussion groups for a solution and saw that you could change the formula field of the model. If you uncomment the lm@call$formula<-frm line in the trimModel1 function the formula field in the summary is displayed correctly. Unfortunately when I run a function from the effects package now I still get the error:

Error in terms.formula(formula, data = data) : 
  'data' argument is of the wrong type

这是因为数据字段仍然不正确.
我发现的另一个可能的解决方案是此功能:

This is because the data field is still incorrect.
Another possible solution I found is this function:

trimModel2 <- function(frm, df) {
  require(LMERConvenienceFunctions)
  require(lme4)

  lm<-do.call("lmer",list(frm,data=df))
  lm.trimmed = romr.fnc(lm, df)
  df = lm.trimmed$data
  # update initial model on trimmed data
  lm<-do.call("lmer",list(frm,data=df))
  mcp.fnc(lm)
  lm
}

当我现在在控制台中键入以下命令时，我没有收到任何错误:

When I now type the following commands in the console I get no errors:

(fm2<-trimModel2(Reaction ~ Days + (Days|Subject),sleepstudy))
plot(allEffects(fm2))

allEffects函数可以工作，但是现在的问题是fm2模型的摘要显示了原始睡眠研究数据.睡眠研究数据并不是一个大问题，但是对于非常大的数据集，有时Rstudio在显示模型时会崩溃.
有谁知道如何使其中一个(或两个)功能正常工作?
我想我必须更改fm1 @ call $ data字段，但我不知道如何.

The allEffects function works but now the problem is that the the summary of the fm2 model displays the raw sleepstudy data. That is not a big problem with the sleepstudy data but with very large datasets sometimes Rstudio crashed when displaying a model.
Does anyone know how to make one (or both) of these functions work correctly?
I think I have to change the fm1@call$data field but I don't know how.

推荐答案

这样做:

trimModel1 <- function(frm, df) {
  require(LMERConvenienceFunctions)
  require(lme4)
  dfname <- as.name(deparse(substitute(df)))

  lm<-lmer(frm,data=df)
  lm.trimmed = romr.fnc(lm, df)
  df = lm.trimmed$data
  # update initial model on trimmed data
  lm<-lmer(frm,data=df)
  lm@call$formula <- frm
  lm@call$data <- dfname
  mcp.fnc(lm)
  lm
}

这是从对象本身获取对象名称的简化方法".

It's the "deparse-substitute trick" to get an object name from the object itself.

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