added funcs to get min/max of lon/lat values

particle-track-and-trace/src/advection/UVGrid.cpp

@@ -55,6 +55,22 @@ int UVGrid::timeStep() const {
   return times[1] - times[0];
 }
 
+double UVGrid::lonMin() const {
+  return this->lons.front();
+}
+
+double UVGrid::lonMax() const {
+  return this->lons.back();
+}
+
+double UVGrid::latMin() const {
+  return this->lats.front();
+}
+
+double UVGrid::latMax() const {
+  return this->lats.back();
+}
+
 void UVGrid::streamSlice(ostream &os, size_t t) {
   for (int x = 0; x < latSize; x++) {
     for (int y = 0; y < lonSize; y++) {

particle-track-and-trace/src/advection/UVGrid.h

@@ -38,6 +38,30 @@ public:
      */
     int timeStep() const;
 
+  /**
+   * Returns the lowest longitudinal value of grid.
+   * @return minimum longitude
+   */
+    double lonMin() const;
+
+  /**
+   * Returns the highest longitudinal value of grid.
+   * @return maximum longitude
+   */
+    double lonMax() const;
+
+  /**
+   * Returns the lowest latitudinal value of grid.
+   * @return minimum latitude
+   */
+    double latMin() const;
+
+  /**
+   * Returns the higehst latitudinal value of grid.
+   * @return maximum latitude
+   */
+    double latMax() const;
+
     /**
      * times, lats, lons are vector of length timeSize, latSize, lonSize respectively.
      * The maintain the following invariant: