text: /*
   *  Mathlib : A C Library of Special Functions
   *  Copyright (C) 1998 Ross Ihaka
   *  Copyright (C) 2000-8 The R Core Team
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation; either version 2 of the License, or
   *  (at your option) any later version.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, a copy is available at
   *  http://www.r-project.org/Licenses/
   *
   *  DESCRIPTION
   *
   *    The lognormal distribution function.
   */
  
  #include "nmath.h"
  #include "dpq.h"
  
  double plnorm(double x, double meanlog, double sdlog, int lower_tail, int log_p)
  {
  #ifdef IEEE_754
      if (ISNAN(x) || ISNAN(meanlog) || ISNAN(sdlog))
  	return x + meanlog + sdlog;
  #endif
      if (sdlog <= 0) ML_ERR_return_NAN;
  
      if (x > 0)
  	return pnorm(log(x), meanlog, sdlog, lower_tail, log_p);
      return R_DT_0;
  }
  