Rename cov --> sigma

include/core/problem/problem.h

@@ -202,7 +202,7 @@ class Problem : public std::enable_shared_from_this<Problem>
                              const VectorComposite& _cov   = VectorComposite());
         FrameBasePtr applyPriorOptions(const TimeStamp& _ts);
         FrameBasePtr setPriorFactor(const VectorComposite &_state,
-                                    const VectorComposite &_cov,
+                                    const VectorComposite &_sigma,
                                     const TimeStamp &_ts,
                                     const double &_time_tol);
         FrameBasePtr setPriorFix(const VectorComposite &_state,

src/problem/problem.cpp

@@ -1082,11 +1082,11 @@ FrameBasePtr Problem::applyPriorOptions(const TimeStamp& _ts)
 }
 
 FrameBasePtr Problem::setPriorFactor(const VectorComposite &_state,
-                                     const VectorComposite &_cov,
+                                     const VectorComposite &_sigma,
                                      const TimeStamp &_ts,
                                      const double &_time_tol)
 {
-    setPriorOptions("factor", _time_tol, _state, _cov);
+    setPriorOptions("factor", _time_tol, _state, _sigma);
     return applyPriorOptions(_ts);
 }