R:nrow [w] * ncol [w]中的错误:使用Neuronet包时二进制运算符的非数字参数 [英] R: Error in nrow[w] * ncol[w] : non-numeric argument to binary operator, while using neuralnet package

问题描述

我正在使用Neuronet软件包来训练分类器. 训练数据如下:

I am using neuralnet package for training a classifier. The training data looks like this:

> head(train_data)
   mvar_12      mvar_40 v10       mvar_1   mvar_2  Labels
1 136.51551310       6   0   656.78784220      0      0
2 145.10739860      87   0    14.21413596      0      0
3 194.74940330       4   0   196.62888080      0      0
4 202.38663480       2   0   702.27307720      0      1
5  60.14319809       9   0    -1.00000000     -1      0
6  95.46539380       6   0   539.09479640      0      0

代码如下:

n <- names(train_data)
f <- as.formula(paste("Labels ~", paste(n[!n %in% "Labels"], collapse = " + ")))
library(neuralnet)
nn <- neuralnet(f, tr_nn, hidden = 4, threshold = 0.01,        
                stepmax = 1e+05, rep = 1, 
                lifesign.step = 1000,
                algorithm = "rprop+")

当我尝试对测试集进行预测时，就会出现问题:

The problem arises when I try to make a prediction for a test set:

pred <- compute(nn, cv_data)

cv_data如下所示:

Where cv_data looks like:

> head(cv_data)
   mvar_12      mvar_40 v10      mvar_1    mvar_2
1 213.84248210       1   9  -1.000000000     -1
2 110.73985680       0   0  -1.000000000     -1
3 152.74463010      14   0 189.521812800     -1
4  64.91646778       7   0  47.854257730     -1
5 141.28878280      12   0 248.557857500      5
6  55.36992840       2   0   4.785425773     -1

为此，我收到一条错误消息:

To this I get an error saying:

Error in nrow[w] * ncol[w] : non-numeric argument to binary operator
In addition: Warning message:
In is.na(weights) : is.na() applied to non-(list or vector) of type 'NULL'

为什么会出现此错误，我该如何解决?

Why do I get this error and how can I fix it?

推荐答案

我刚刚遇到了同样的问题.查看compute函数的源代码，我们可以看到它假定了结果属性之一(即weights)仅在网络完美无缺地完成训练后才定义.

I just came up against the very same problem. Checking the source code of the compute function we can see that it assumes one of the resulting attributes (i.e. weights) only defined when the network finishes the training flawless.

> trace("compute",edit=TRUE)
function (x, covariate, rep = 1) {
    nn <- x
    linear.output <- nn$linear.output
    weights <- nn$weights[[rep]]
    [...]
}

我认为真正的问题在于，一旦达到stepmax值，neuralnet不会保存当前网络，稍后会在compute代码中引起此错误.

I think the real problem lies on the fact that neuralnet doesn't save the current network once reached the stepmax value, causing this error later in the compute code.

修改

看来您可以通过注释行 65 &来避免此重置calculate.neuralnet函数的 66

It seems you can avoid this reset by commenting lines 65 & 66 of the calculate.neuralnet function

> fixInNamespace("calculate.neuralnet", pos="package:neuralnet")
[...]
#if (reached.threshold > threshold) 
#    return(result = list(output.vector = NULL, weights = NULL))
[...]

然后一切都变成一种魅力:)

Then everything works as a charm :)

这篇关于R:nrow [w] * ncol [w]中的错误:使用Neuronet包时二进制运算符的非数字参数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！