corr bug found by Antti: "stdv x" was "variance y".

pub/CHANGELOG

@@ -2,7 +2,9 @@ Release 2.3.1c
 
 - Updated dependence:
   - now requires cmake 2.8.12 (older version were untested)
-  
+- Bug fix:
+  - "stdv" was variance. Now "var" and "stdv" are available
+
 Release 2.3.1b of 22sep15
 
 - Improved functionality:

pub/lib/geni.cpp

@@ -151,12 +151,12 @@ void geni_avge( double* r, double* dr, int n, const vector<RObjVecNum>& a )
         *dr = 0; // TODO better estimate
 }
 
-//! Standard deviation.
+//! Sample variance.
 
-void geni_stdv( double* r, double* dr, int n, const vector<RObjVecNum>& a )
+void geni_variance( double* r, double* dr, int n, const vector<RObjVecNum>& a )
 {
     if ( n<2 )
-        throw S("Cannot compute corrected standard deviation for sample size < 2");
+        throw S("Cannot compute sample variance for sample size < 2");
     double p=0, pp=0, q=0;
     for ( int i=0; i<n; i++ ) {
         pp = p + ( a[0]->to_r(i) - p ) / (i+1);
@@ -168,6 +168,16 @@ void geni_stdv( double* r, double* dr, int n, const vector<RObjVecNum>& a )
         *dr = 0; // TODO better estimate
 }
 
+//! Sample standard deviation.
+
+void geni_stdv( double* r, double* dr, int n, const vector<RObjVecNum>& a )
+{
+    geni_variance( r, dr, n, a );
+    *r = sqrt( *r );
+    if( dr )
+        *dr = 0; // TODO better estimate
+}
+
 //! Integral.
 
 void geni_integral( double* r, double* dr, int n, const vector<RObjVecNum>& a )
@@ -308,8 +318,10 @@ void NGeni::initialize()
                 "sum of y" ))->register_me();
     (new CGeni( "avge", 1, "y", geni_avge, "a",
                 "average of y" ))->register_me();
+    (new CGeni( "var", 1, "y", geni_variance, "a",
+                "sample variance of y" ))->register_me();
     (new CGeni( "stdv", 1, "y", geni_stdv, "a",
-                "corrected sample standard deviation of x" ))->register_me();
+                "sample standard deviation of y" ))->register_me();
     (new CGeni( "integral", 2, "x,y", geni_integral, "ab",
                 "integral d(x) of y" ))->register_me();
     (new CGeni( "cog", 2, "x,y", geni_cog, "a",