# HG changeset patch
# User John W. Eaton <jwe@octave.org>
# Date 1294178239 18000
# Node ID c2f44cba24c9d9c58471a1446dfc733ee4df40f9
# Parent  9e8497537319a16db4d344e1940f7a52716a14cd
improve display of percentage full when printing sparse matrices

diff -r 9e8497537319 -r c2f44cba24c9 src/ChangeLog
--- a/src/ChangeLog	Tue Jan 04 14:09:16 2011 -0500
+++ b/src/ChangeLog	Tue Jan 04 16:57:19 2011 -0500
@@ -1,3 +1,8 @@
+2011-01-04  John W. Eaton  <jwe@octave.org>
+
+	* ov-base-sparse.cc (octave_base_sparse<T>::print_raw): Improve
+	display of percentage full.  Bug #32011.
+
 2011-01-04  John W. Eaton  <jwe@octave.org>
 
 	* ov-typeinfo.cc (Ftypeinfo): Return cell array of character
diff -r 9e8497537319 -r c2f44cba24c9 src/ov-base-sparse.cc
--- a/src/ov-base-sparse.cc	Tue Jan 04 14:09:16 2011 -0500
+++ b/src/ov-base-sparse.cc	Tue Jan 04 16:57:19 2011 -0500
@@ -321,7 +321,31 @@
   double dnel = matrix.numel ();
 
   if (dnel > 0)
-    os << " [" << std::setprecision (2) << (nz / dnel * 100) << "%]";
+    {
+      double pct = (nz / dnel * 100);
+
+      int prec = 2;
+
+      // Display at least 2 significant figures and up to 4 as we
+      // approach 100%.  Avoid having limited precision of the display
+      // result in reporting 100% for matrices that are not actually
+      // 100% full.
+
+      if (pct == 100)
+        prec = 3;
+      else
+        {
+          if (pct > 99.9)
+            prec = 4;
+          else if (pct > 99)
+            prec = 3;
+
+          if (pct > 99.99)
+            pct = 99.99;
+        }
+
+      os << " [" << std::setprecision (prec) << pct << "%]";
+    }
 
   os << ")\n";