doc: Shorten some long subsection names in Manual. Remove excess spaces from ends of @menu definitions. * doc/interpreter/arith.txi, doc/interpreter/basics.txi, doc/interpreter/bugs.txi, doc/interpreter/container.txi, doc/interpreter/data.txi, doc/interpreter/diagperm.txi, doc/interpreter/diffeq.txi, doc/interpreter/emacs.txi, doc/interpreter/expr.txi, doc/interpreter/external.txi, doc/interpreter/func.txi, doc/interpreter/grammar.txi, doc/interpreter/gui.txi, doc/interpreter/install.txi, doc/interpreter/intro.txi, doc/interpreter/io.txi, doc/interpreter/java.txi, doc/interpreter/linalg.txi, doc/interpreter/matrix.txi, doc/interpreter/nonlin.txi, doc/interpreter/numbers.txi, doc/interpreter/octave.texi, doc/interpreter/optim.txi, doc/interpreter/plot.txi, doc/interpreter/preface.txi, doc/interpreter/quad.txi, doc/interpreter/sparse.txi, doc/interpreter/stats.txi, doc/interpreter/stmt.txi, doc/interpreter/strings.txi, doc/interpreter/system.txi, doc/interpreter/var.txi: Shorten some long subsection names in Manual. Remove excess spaces from ends of @menu definitions.

#include "mex.h"

void
mexFunction (int nlhs, mxArray* plhs[],
             int nrhs, const mxArray* prhs[])
{
  mwSize n;
  mwIndex i;
  double *vri, *vro;
  
  if (nrhs != 1 || ! mxIsNumeric (prhs[0]))
    mexErrMsgTxt ("ARG1 must be a matrix");

  n = mxGetNumberOfElements (prhs[0]);
  plhs[0] = mxCreateNumericArray 
    (mxGetNumberOfDimensions (prhs[0]), mxGetDimensions (prhs[0]),
     mxGetClassID (prhs[0]), mxIsComplex (prhs[0]));
  vri = mxGetPr (prhs[0]);
  vro = mxGetPr (plhs[0]);

  if (mxIsComplex (prhs[0]))
    {
      double *vii, *vio;
      vii = mxGetPi (prhs[0]);
      vio = mxGetPi (plhs[0]);

      for (i = 0; i < n; i++)
        {
          vro[i] = vri[i] * vri[i] - vii[i] * vii[i];
          vio[i] = 2 * vri[i] * vii[i];
        }
    }
  else
    {
      for (i = 0; i < n; i++)
        vro[i] = vri[i] * vri[i];
    }
}