Drizzled Public API Documentation

ln.cc

00001 /* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
00002  *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
00003  *
00004  *  Copyright (C) 2008 Sun Microsystems, Inc.
00005  *
00006  *  This program is free software; you can redistribute it and/or modify
00007  *  it under the terms of the GNU General Public License as published by
00008  *  the Free Software Foundation; version 2 of the License.
00009  *
00010  *  This program is distributed in the hope that it will be useful,
00011  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00012  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00013  *  GNU General Public License for more details.
00014  *
00015  *  You should have received a copy of the GNU General Public License
00016  *  along with this program; if not, write to the Free Software
00017  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
00018  */
00019 
00020 #include <config.h>
00021 #include <math.h>
00022 #include "ln.h"
00023 
00024 namespace drizzled
00025 {
00026 
00028 double Item_func_ln::val_real()
00029 {
00030   assert(fixed == 1);
00031   double value= args[0]->val_real();
00032   if ((null_value= args[0]->null_value))
00033     return 0.0;
00034   if (value <= 0.0)
00035   {
00036     signal_divide_by_null();
00037     return 0.0;
00038   }
00039   return log(value);
00040 }
00041 
00042 } /* namespace drizzled */