title: neural net - undefined column selected
body: <h1>Data Partition</h1>
  
  <p>I have several factor variables so I decided to use dummy variables instead for ANN. </p>
  
  <pre><code>set.seed(222)
  m &lt;- model.matrix( ~price+month+year+area+larea+otype+cid+rid+did+renovation+nrooms+nbeds+nbaths+nbalcs+wfloor+status, data = data)
  ind &lt;- sample(2, nrow(m), replace = TRUE, prob = c(0.8, 0.2))
  training &lt;- m[ind==1,]
  testing &lt;- m[ind==2,]
  </code></pre>
  
  <h1>neural net</h1>
  
  <pre><code>n &lt;- neuralnet(price~.,
                  data = training,
                  hidden = 1,
                  err.fct = "sse",
                  linear.output = FALSE)
  </code></pre>
  
  <blockquote>
    <p>Error in <code>[.data.frame</code>(data, , model.list$variables) : 
      undefined columns selected</p>
  </blockquote>
  
  <p>I use dot because I have 94 explanatory variables. when I run price on two explanatory variables to see what the problem was it worked. There is some problem with dot, is it only used for linear regression and I got it wrong? how can I solve this problem?</p>