title: R glmnet as.matrix() error message
body: <p>I'm trying to use the <code>glmnet</code> package on a dataset.  I'm using <code>cv.glmnet()</code> to get a lambda value for <code>glmnet()</code>.  I'm excluding columns 1,2,7,12 as they are: id column, response column, contain NA's, and contain NA's.</p>
  
  <p>Here's the dataset and error message:</p>
  
  <pre><code>&gt; head(t2)
    X1 X2        X3 X4 X5         X6    X7 X8 X9 X10 X11 X12
  1  1  1 0.7661266 45  2 0.80298213  9120 13  0   6   0   2
  2  2  0 0.9571510 40  0 0.12187620  2600  4  0   0   0   1
  3  3  0 0.6581801 38  1 0.08511338  3042  2  1   0   0   0
  4  4  0 0.2338098 30  0 0.03604968  3300  5  0   0   0   0
  5  5  0 0.9072394 49  1 0.02492570 63588  7  0   1   0   0
  6  6  0 0.2131787 74  0 0.37560697  3500  3  0   1   0   1
  &gt; str(t2)
  'data.frame':   150000 obs. of  12 variables:
   $ X1 : int  1 2 3 4 5 6 7 8 9 10 ...
   $ X2 : int  1 0 0 0 0 0 0 0 0 0 ...
   $ X3 : num  0.766 0.957 0.658 0.234 0.907 ...
   $ X4 : int  45 40 38 30 49 74 57 39 27 57 ...
   $ X5 : int  2 0 1 0 1 0 0 0 0 0 ...
   $ X6 : num  0.803 0.1219 0.0851 0.036 0.0249 ...
   $ X7 : int  9120 2600 3042 3300 63588 3500 NA 3500 NA 23684 ...
   $ X8 : int  13 4 2 5 7 3 8 8 2 9 ...
   $ X9 : int  0 0 1 0 0 0 0 0 0 0 ...
   $ X10: int  6 0 0 0 1 1 3 0 0 4 ...
   $ X11: int  0 0 0 0 0 0 0 0 0 0 ...
   $ X12: int  2 1 0 0 0 1 0 0 NA 2 ...
  
  &gt; cv1 &lt;- cv.glmnet(as.matrix(t2[,-c(1,2,7,12)]), t2[,2], family="binomial")
  Error in as.matrix(cbind2(1, newx) %*% nbeta) : 
    error in evaluating the argument 'x' in selecting a method for function 'as.matrix': Error in t(.Call(Csparse_dense_crossprod, y, t(x))) : 
    error in evaluating the argument 'x' in selecting a method for function 't': Error: invalid class 'NA' to dup_mMatrix_as_dgeMatrix
  &gt; cv1 &lt;- cv.glmnet(as.matrix(t2[,-c(1,2,7,12)]), t2[,2], family="multinomial")
  Error in t(.Call(Csparse_dense_crossprod, y, t(x))) : 
    error in evaluating the argument 'x' in selecting a method for function 't': Error: invalid class 'NA' to dup_mMatrix_as_dgeMatrix
  </code></pre>
  
  <p>Any suggestions?</p>