new file mode 100644
--- /dev/null
+++ b/src/DLD-FUNCTIONS/betainc.cc
@@ -0,0 +1,164 @@
+/*
+
+Copyright (C) 1997 John W. Eaton
+
+This file is part of Octave.
+
+Octave 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, or (at your option) any
+later version.
+
+Octave 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 Octave; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "lo-specfun.h"
+
+#include "defun-dld.h"
+#include "error.h"
+#include "gripes.h"
+#include "oct-obj.h"
+#include "utils.h"
+
+DEFUN_DLD (betainc, args, ,
+  "betainc (x, a, b)\n\
+\n\
+Compute the incomplete beta function\n\
+\n\
+  betainc(x,a,b) = beta(a,b)^(-1) \\int_0^x t^(a-1) (1-t)^(b-1) dt\n\
+\n\
+The sizes of x, a, and b must agree.")
+{
+  octave_value retval;
+
+  int nargin = args.length ();
+
+  if (nargin == 3)
+    {
+      octave_value x_arg = args(0);
+      octave_value a_arg = args(1);
+      octave_value b_arg = args(2);
+
+      if (x_arg.is_scalar_type ())
+	{
+	  double x = x_arg.double_value ();
+
+	  if (a_arg.is_scalar_type ())
+	    {
+	      double a = a_arg.double_value ();
+
+	      if (! error_state)
+		{
+		  if (b_arg.is_scalar_type ())
+		    {
+		      double b = b_arg.double_value ();
+
+		      if (! error_state)
+			retval = betainc (x, a, b);
+		    }
+		  else
+		    {
+		      Matrix b = b_arg.matrix_value ();
+
+		      if (! error_state)
+			retval = betainc (x, a, b);
+		    }
+		}
+	    }
+	  else
+	    {
+	      Matrix a = a_arg.matrix_value ();
+
+	      if (! error_state)
+		{
+		  if (b_arg.is_scalar_type ())
+		    {
+		      double b = b_arg.double_value ();
+
+		      if (! error_state)
+			retval = betainc (x, a, b);
+		    }
+		  else
+		    {
+		      Matrix b = b_arg.matrix_value ();
+
+		      if (! error_state)
+			retval = betainc (x, a, b);
+		    }
+		}
+	    }
+	}
+      else
+	{
+	  Matrix x = x_arg.matrix_value ();
+
+	  if (a_arg.is_scalar_type ())
+	    {
+	      double a = a_arg.double_value ();
+
+	      if (! error_state)
+		{
+		  if (b_arg.is_scalar_type ())
+		    {
+		      double b = b_arg.double_value ();
+
+		      if (! error_state)
+			retval = betainc (x, a, b);
+		    }
+		  else
+		    {
+		      Matrix b = b_arg.matrix_value ();
+
+		      if (! error_state)
+			retval = betainc (x, a, b);
+		    }
+		}
+	    }
+	  else
+	    {
+	      Matrix a = a_arg.matrix_value ();
+
+	      if (! error_state)
+		{
+		  if (b_arg.is_scalar_type ())
+		    {
+		      double b = b_arg.double_value ();
+
+		      if (! error_state)
+			retval = betainc (x, a, b);
+		    }
+		  else
+		    {
+		      Matrix b = b_arg.matrix_value ();
+
+		      if (! error_state)
+			retval = betainc (x, a, b);
+		    }
+		}
+	    }
+	}
+    }
+  else
+    print_usage ("betainc");
+
+  return retval;
+}
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; End: ***
+*/
+