/** The static initializer sets up the options vector */
 static {
   options.addElement(new Option("\tAlpha star. (default = 0.5).", "A", 1, "-A <0-1>"));
   options.addElement(new Option("\tSigma. (default = 1.0).", "S", 1, "-S <num>"));
   options.addElement(
       new Option(
           "\tR. All points that are far away more than this value have a zero similarity. (default = -1).",
           "R",
           1,
           "-R <num>"));
   options.addElement(
       new Option("\tUse sparse matrix representation. (default = false).", "M", 0, "-M"));
 }
 /**
  * Returns an enumeration describing the available options.
  *
  * <p>
  *
  * @return an enumeration of all the available options
  */
 public Enumeration listOptions() {
   return options.elements();
 }