gnumeric r17246 - in trunk: . plugins/fn-financial

[mortenw svn gnome org]

Author: mortenw
Date: Sat Mar 28 16:38:15 2009
New Revision: 17246
URL: http://svn.gnome.org/viewvc/gnumeric?rev=17246&view=rev

Log:
2009-03-28  Morten Welinder  <terra gnome org>

	* functions.c (gnm_range_xirr): Try insanely close to -1 if all
	else fails.



Modified:
   trunk/NEWS
   trunk/plugins/fn-financial/ChangeLog
   trunk/plugins/fn-financial/functions.c

Modified: trunk/NEWS
==============================================================================
--- trunk/NEWS	(original)
+++ trunk/NEWS	Sat Mar 28 16:38:15 2009
@@ -3,6 +3,7 @@
 Morten:
 	* Handle elapsed time formats better on text export.
 	* Plug leak.
+	* Improve XIRR a bit.
 
 --------------------------------------------------------------------------
 Gnumeric 1.9.5

Modified: trunk/plugins/fn-financial/functions.c
==============================================================================
--- trunk/plugins/fn-financial/functions.c	(original)
+++ trunk/plugins/fn-financial/functions.c	Sat Mar 28 16:38:15 2009
@@ -1978,7 +1978,9 @@
 
 	status = goal_seek_newton (&xirr_npv, NULL, &data, &p, rate0);
 	if (status != GOAL_SEEK_OK) {
+		double r;
 		int i;
+
 		for (i = 1; i <= 1024; i += i) {
 			(void)goal_seek_point (&xirr_npv, &data, &p, -1 + 10.0 / (i + 9));
 			(void)goal_seek_point (&xirr_npv, &data, &p, i);
@@ -1986,6 +1988,14 @@
 			if (status == GOAL_SEEK_OK)
 				break;
 		}
+
+		/* Try insanely close to -1.  */
+		for (r = GNM_EPSILON; r < 0.02; r *= 2) {
+			(void)goal_seek_point (&xirr_npv, &data, &p, -1 + r);
+			status = goal_seek_bisection (&xirr_npv, &data, &p);
+			if (status == GOAL_SEEK_OK)
+				break;
+		}
 	}
 
 	if (status == GOAL_SEEK_OK) {