getMethod（“ summary”，签名=“ FitDiff”）中的错误 [英] Error in getMethod("summary", signature = "FitDiff")

问题描述

我正在使用 semTools :: compareFit 比较lavaan对象。它抛出了一个非常奇怪的错误消息。

I am comparing lavaan objects using semTools::compareFit. It is throwing a very strange error message.

我也尝试了以下可重现的示例：

I tried also the following reproducible example:

data("HolzingerSwineford1939",package="lavaan")
HS.modelA <- ' visual  =~ x1 + x2 + x3
              textual =~ x4 + x5 + x6
              speed   =~ x7 + x8 + x9'

HS.modelB<- ' visual  =~ x1 + x2
              textual =~ x4 + x5 + x6
              speed   =~ x7 + x8 + x9'
fit.A<- cfa(HS.modelA, data = HolzingerSwineford1939)
fit.B<- cfa(HS.modelB, data = HolzingerSwineford1939)
semTools::compareFit(fit.A,fit.B)

它返回：

getMethod（ summary，signature = FitDiff）中的错误：未找到函数'summary'和签名FitDiff的方法

Error in getMethod("summary", signature = "FitDiff") : no method found for function 'summary' and signature FitDiff

也，因为代码位于函数内部，但是我想查看屏幕上显示的输出，所以我还包括：

Also, as the code is inside a function, but I would like to see the output printed in the screen, I also included:

result<-semTools::compareFit(fit.A,fit.B)
semTools::saveFile(result, file="",what="summary", tableFormat=FALSE)

这将返回

Length Class Mode

Length Class Mode

  1 FitDiff      S4

我在第一条错误消息中看到提及与概述和方法有关的内容...我有一些S3 概述方法，尝试将其形式化以供个人使用...不确定是否相关...我是否可能弄乱了某些东西？
RStudio安装中的多个项目中都在发生这种情况...给人的印象是它以前工作过...

I see the mention in the first error message something related to summary and methods... I have some S3 summary methods, trying to formalize in a package for personal use... not sure if it is related... is it possible I have messed up something? It is happening in more than one project in a RStudio installation... I have the impression it worked before...

我非常感谢您的帮助。

推荐答案

我在这里报告我如何规避此问题。

I am reporting here how I circumvented the problem.

正在发生的事情的结论在这里：

这确实是S3方法弄乱了S4方法分派的问题。

This is really an issue with S3 methods messing up the S4 method dispatch.

如果我加载 showMethods（summary）在加载semTools软件包之前，我得到：

If I load showMethods(summary) before loading the semTools package, I get:

Function "summary":
 <not an S4 generic function>)

但是如果我加载 showMethods（summary） 加载后，我得到：

But if I load showMethods(summary) after loading it, I get:

Function: summary (package base)
object="ANY"
object="FitDiff"
    (inherited from: object="ANY")
object="lavaan"
object="lavaanList"
object="mle"

因此，解决方案：

考虑 FitDiff 对象结构，我创建了 summary.FitDiff （s3方法）：

Considering the FitDiff object structure, I created a summary.FitDiff (s3 method):

summary.FitDiff<-function(object){
          print(object@nested)
          return(object@fit)
}

，并且此摘要方法与 FitDiff 对象：

a<-semTools::compareFit(fit.A,fit.B)
summary(a)

这不是一个完美的解决方案，理想的解决方案应该涉及如何指定s3方法而不弄乱所有内容可能是s4方法，但是我对s4方法没有足够的了解...它现在解决了我的问题...

This is not a perfect solution, the ideal solution should involve something with how to specify s3 methods without messing up all possible s4method, but I have not sufficient knowledge about s4 methods... It solved my problem for now...

这篇关于getMethod（“ summary”，签名=“ FitDiff”）中的错误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！