在R中：is.data.frame（data）中的错误：找不到对象”，C5.0图 [英] in R: Error in is.data.frame(data) : object '' not found, C5.0 plot

问题描述

此问题类似于Stackoverflow上的其他一些问题（此处，此处和此处），但又相差太大，因此我无法推断这些我的情况的答案。

This question is similar to some other questions on Stackoverflow (here, here and here), but different enough so that I cannot extrapolate those answers to my case.

我有一个函数可以拟合C5.0模型，然后尝试绘制模型。

I have a function in which I fit a C5.0 model and than try to plot the model.

train_d <- globald[train_ind,c(features,21)]
model <- C5.0(binclass ~ .,data=train_d,trials=10)

binclass 是一列我的训练/测试数据中的名称（globald是一个数据框，我在该数据框中用 _ind 索引和列 c（3：12,21），其中列21名为 bin类）。拟合效果很好。但是，当我同时添加行

binclass is a column name in my training/test data (globald is a dataframe from which I subset rows with _ind indices and columns c(3:12,21), where column 21 is named binclass). Fitting works well. However, when I also add the line

plot(model,trial=0)

然后出现以下错误： is.data.frame（data）中的错误：找不到对象'train_d'。

then I get the following error: Error in is.data.frame(data) : object 'train_d' not found.

在拟合模型时，如何找到并正确使用 train_d ，但是在绘制时， train_d 找不到地方了吗？并且，关于如何解决此问题的任何建议。

How is it possible that when fitting the model, train_d is found and used correctly, but while plotting, train_d is nowhere to be found? And, any suggestion of how to solve this issue. Namespaces in [r] remain a mystery to me.

一个最小的运行示例如下：

A minimal running example is the following:

f <- function(){
    library(C50)
    set.seed(1)
    class = c(1,2)
    d <- data.frame(feature1 = sample(1:10,10,replace=TRUE), feature2 = 1:10, binclass = class)
    d$binclass <- as.factor(d$binclass)
    model <- C5.0(binclass ~ ., data=d)
    plot(model)   
}

调用 f（）会导致以下错误： is.data.frame（data）中的错误：找不到对象'd'

Calling f() results in the following error: Error in is.data.frame(data) : object 'd' not found

编辑：
根据MrFlick的回答，似乎是导致此问题的原因是C5.0代码中的错误。 Pascal和MrFlick指出了一些解决方法。

As per the answer from MrFlick, it seems that the cause of this problem is a bug in the C5.0 code. There are some workarounds are indicated by Pascal and MrFlick.

推荐答案

涉及到代码中似乎确实存在错误。在适当的环境中评估命令。问题似乎出在 C50 :: model.frame.C5.0 函数中。我能找到的最干净的解决方法是在模型中添加 terms 属性。这将有助于封装函数环境。

There does appear to be a bug in the code when it comes to evaluating the command in the proper environment. The problem appears to be in the C50::model.frame.C5.0 function. The "cleanest" work around I could find was to add a terms property to your model. This will help encapsulate the function environment.

f <- function(){
    library(C50)
    set.seed(1)
    class = c(1,2)
    d <- data.frame(feature1 = sample(1:10,10,replace=TRUE), feature2 = 1:10, binclass = class)
    d$binclass <- as.factor(d$binclass)
    model <- C5.0(binclass ~ ., data=d)
    model$terms <- eval(model$call$formula)   #<---- Added line
    plot(model)   
}

这篇关于在R中：is.data.frame（data）中的错误：找不到对象”，C5.0图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！