title: Working with neuralnet in R for the first time: get "requires numeric/complex matrix/vector arguments"
body: <p>I'm in the process of attempting to learn to work with neural networks in R. As a learning problem, I've been using the <a href="http://www.kaggle.com/c/titanic-gettingStarted" rel="noreferrer">following problem</a> over at <a href="https://www.kaggle.com" rel="noreferrer">Kaggle</a>:</p>
  
  <p>Don't worry, this problem is specifically designed for people to learn with, there's no reward tied to it.</p>
  
  <p>I started with a simple logistic regression, which was great for getting my feet wet. Now I'd like to learn to work with neural networks. My training data looks like this (Column:Row):</p>
  
  <pre><code>- survived: 1
  - pclass:   3
  - sex:      male
  - age:      22.0
  - sibsp:    1
  - parch:    0
  - ticket:   PC 17601
  - fare:     7.25
  - cabin:    C85
  - embarked: S
  </code></pre>
  
  <p>My starting R code looks like this:</p>
  
  <pre><code>&gt; net &lt;- neuralnet(survived ~ pclass + sex + age + sibsp +
                     parch + ticket + fare + cabin + embarked, 
                     train, hidden=10, threshold=0.01)
  </code></pre>
  
  <p>When I run this line of code I get the following error:</p>
  
  <pre><code>Error in neurons[[i]] %*% weights[[i]] : 
    requires numeric/complex matrix/vector arguments
  </code></pre>
  
  <p>I understand that the problem is in the way I'm presenting my input variables but I'm too much of a novice to understand what I need to do to correct this. Can anyone help?</p>
  
  <p>Thanks!</p>