title: length of 'dimnames' [2] not equal to array extent when using corrplot function from a matrix read from a csv file
body: <p>I wanna read the data from a csv file, save it as a matrix and use it for visualization.</p>
  
  <pre><code>data&lt;-read.table("Desktop/Decision_Tree/cor_test_.csv",header = F,sep = ",")
  
  data
  V1    V2    V3   V4  V5     V6
  1  1.00  0.00  0.00 0.00  0.00  0
  2  0.11  1.00  0.00 0.00  0.00  0
  3  0.12  0.03  1.00 0.00  0.00  0
  4 -0.04  0.54  0.32 1.00  0.00  0
  5 -0.12  0.57 -0.09 0.26  1.00  0
  6  0.21 -0.04  0.24 0.18 -0.21  1
  </code></pre>
  
  <p>It goes well. But then:</p>
  
  <pre><code>corrplot(data, method = 'color', addCoef.col="grey")
  </code></pre>
  
  <p>It is said that:</p>
  
  <blockquote>
    <p>Error in matrix(unlist(value, recursive = FALSE, use.names = FALSE), nrow = nr,  :
    length of 'dimnames' [2] not equal to array extent</p>
  </blockquote>
  
  <p>I don't know how to solve it.</p>