diff --git a/include/uvdata.h b/include/uvdata.h
index 889b066..d98e2c8 100644
--- a/include/uvdata.h
+++ b/include/uvdata.h
@@ -21,6 +21,7 @@ class UVDataStorage
  std::vector<real> u, v, u2;
  size_t            nx = 0, ny = 0;
  Metric            metric;
+ MString           unit;
 
  UVDataStorage() = default;
  real D(real lon1, real lat1, real lon2, real lat2) const
@@ -38,6 +39,8 @@ class UVDataStorage
  real Ud(size_t ix, size_t iy) const { return IsCoast(ix, iy) ? 0.0 : U(ix, iy); }
  real Vd(size_t ix, size_t iy) const { return IsCoast(ix, iy) ? 0.0 : V(ix, iy); }
 
+ void SetUnit(const MString& str) { unit = str; }
+
  public:
  enum STPOINT
  {
@@ -82,7 +85,22 @@ class UVDataStorage
  bool IsCoast(size_t i) const { return U(i) == fillval || V(i) == fillval; }
  bool IsCoast(size_t ix, size_t iy) const { return U(ix, iy) == fillval || V(ix, iy) == fillval; }
 
+ bool IsFill(size_t i) const { return IsCoast(i); }
+ bool IsFill(size_t ix, size_t iy) const { return IsCoast(ix, iy); }
+
  static real Fillval() { return fillval; }
+
+ const MString& Unit() const { return unit; }
+
+ const MString DUnit() const
+ {
+  switch(metric)
+  {
+  case(Metric::EUCLID): return "";
+  case(Metric::SPHERIC): return "km";
+  }
+  return "";
+ }
 };
 
 template<class OneVarData, bool isgrid> class UVDataDims;
@@ -128,6 +146,7 @@ template<class OneVarData> class UVDataDims<OneVarData, true>: public UVDataStor
     U2(i) = u(i) * u(i) + v(i) * v(i);
    }
   }
+  SetUnit(u.Unit());
  }
 
  public:
@@ -138,6 +157,9 @@ template<class OneVarData> class UVDataDims<OneVarData, true>: public UVDataStor
 
  real XStep() const { return xstep; }
  real YStep() const { return ystep; }
+
+ real Ix2Lon(size_t ix) const { return x0 + ix * xstep; }
+ real Iy2Lat(size_t iy) const { return y0 + iy * ystep; }
 };
 
 template<class OneVarData> class UVDataDims<OneVarData, false>: public UVDataStorage