[Boost-sandbox-cvs] boost-sandbox/boost/units measurement.hpp, 1.10, 1.11

[Matthias S. <mat...@us...>]

Update of /cvsroot/boost-sandbox/boost-sandbox/boost/units
In directory sc8-pr-cvs3.sourceforge.net:/tmp/cvs-serv2560

Modified Files:
	measurement.hpp 
Log Message:
need to fix to emulate NIST CODATA formatting...


Index: measurement.hpp
===================================================================
RCS file: /cvsroot/boost-sandbox/boost-sandbox/boost/units/measurement.hpp,v
retrieving revision 1.10
retrieving revision 1.11
diff -u -d -r1.10 -r1.11
--- measurement.hpp	4 Apr 2007 20:04:25 -0000	1.10
+++ measurement.hpp	4 Apr 2007 21:18:04 -0000	1.11
@@ -316,20 +316,33 @@
     boost::io::ios_width_saver width_saver(os);
     boost::io::ios_flags_saver flags_saver(os);
 
-    os << std::setprecision(13) 
-       << std::setw(21) 
-       << std::scientific
-       << val.value();
-
+    os << std::setw(21);
+    
     if (val.uncertainty() > Y(0))
+    {
+        const Y relative_uncertainty = std::abs(val.uncertainty()/val.value());
+    
+        const long  exponent = std::log10(relative_uncertainty),
+                    digits_of_precision = std::ceil(std::abs(exponent))+3;
+        
+        // should try to replicate NIST CODATA syntax 
+        os << std::setprecision(digits_of_precision) 
+           //<< std::setw(digits_of_precision+8) 
+           //<< std::scientific
+           << val.value();
+//           << long(10*(relative_uncertainty/std::pow(Y(10),Y(exponent))));
+
         os << " (rel. unc. = " 
            << std::setprecision(1) 
            << std::setw(7) 
            << std::scientific
-           << std::abs(val.uncertainty()/val.value()) << ")";
+           << relative_uncertainty << ")";
+    }
     else
-        os << " (exact)";
-        
+    {
+        os << val.value() << " (exact)";
+    }
+    
     return os;
 }