1.  NAME

  isdef - Check if a variable is defined

  2.  SYNOPSIS

  a = isdef(w)

  3.  DESCRIPTION

  This function checks if a variable is defined. With higher version of
  Matlab, it has become obsolete, as one can use the Matlab function
  exist.

  4.  PARAMETERS

     w  The output of Matlab function who.

     var
        A string containing the variable name.

  5.  RETURNS

     a  An array with 1 if the corresponding variable is defined,0
        otherwise.

  6.  AUTHORS

  Pierre Jaccard, Geophysical Institute, University of Bergen, 1999