title: Correlation matrix from categorical and non-categorical variables (Matlab)
body: <p>In Matlab, I have a dataset in a table of the form:</p>
  
  <pre><code>SCHOOL  SEX  AGE  ADDRESS  STATUS  JOB  GUARDIAN  HEALTH  GRADE
  UR      F    12   U        FT      TEA  MOTHER    1       11
  GB      M    22   R        FT      SER  FATHER    5       15
  GB      M    12   R        FT      OTH  FATHER    3       12
  GB      M    11   R        PT      POL  FATHER    2       10
  </code></pre>
  
  <p>Where some variables are binary, some are categorical, some numerical. Would it be possible to extract from it a correlation matrix, with the correlation coefficients between the variables? I tried using both <code>corrcoef</code> and <code>corrplot</code> from the econometrics toolbox, but I come across errors such as 'observed data must be convertible to type double'.</p>
  
  <p>Anyone would have a take on how this can be done? Thank you.</p>