[Positioner] Measurement: use floats, not doubles

Use floats variables for the average and variance.

owlps-positioner/src/measurement.cc

@@ -123,10 +123,10 @@ void Measurement::recalculate_average()
 void Measurement::update_average(ss_t ss_dbm)
 {
   // Convert the new SS in mW:
-  double ss_mw = pow(10, static_cast<double>(ss_dbm) / 10.0) ;
+  float ss_mw = pow(10, static_cast<float>(ss_dbm) / 10.0) ;
 
   // Update the average:
-  double delta = ss_mw - average_mw ;
+  float delta = ss_mw - average_mw ;
   average_mw += delta / ss_list.size() ;
   average_dbm = 10.0 * log10(average_mw) ;
 

owlps-positioner/src/measurement.hh

@@ -26,15 +26,15 @@ protected:
   /// List of signal strengths captured (in dBm)
   std::map<pkt_id_t, ss_t> ss_list ;
   /// Average of all the captured signal strengths (dBm)
-  double average_dbm ;
+  float average_dbm ;
   /// Average of all the captured signal strengths (mW)
-  double average_mw ;
+  float average_mw ;
   /// Variance of all the captured signal strengths
-  double variance ;
+  float variance ;
 
 private:
   /// Intermediate variable used to compute the variance
-  double variance_m2 ;
+  float variance_m2 ;
 
 
 protected:
@@ -62,8 +62,8 @@ public:
   /** @name Read accessors */
   //@{
   AccessPoint* get_ap() const ;
-  double get_average_dbm() const ;
-  double get_variance() const ;
+  float get_average_dbm() const ;
+  float get_variance() const ;
   int get_nb_ss() const ;
   //@}
 
@@ -116,13 +116,13 @@ inline AccessPoint* Measurement::get_ap() const
 }
 
 
-inline double Measurement::get_average_dbm() const
+inline float Measurement::get_average_dbm() const
 {
   return average_dbm ;
 }
 
 
-inline double Measurement::get_variance() const
+inline float Measurement::get_variance() const
 {
   return variance ;
 }

owlps-positioner/src/referencepoint.cc

@@ -257,7 +257,7 @@ float ReferencePoint::friis_indexes_for_ap(
         measurements.find(ap_mac) ;
       if (measurement != measurements.end())
         {
-          double ss = measurement->second.get_average_dbm() ;
+          float ss = measurement->second.get_average_dbm() ;
           assert((*request)->get_mobile()) ;
           float mobile_gain =
             (*request)->get_mobile()->get_antenna_gain() ;