refactor: add functions to transect plot for PT and LR

clients/python/sliderule/ipysliderule.py

@@ -2508,14 +2508,12 @@ def plot(self, **kwargs):
         kwargs.setdefault('cycle', 0)
         kwargs.setdefault('RGT', 0)
         kwargs.setdefault('GT', 0)
-        kwargs.setdefault('LR', 0)
-        kwargs.setdefault('PT', 0)
         # variable to plot
         column = kwargs['column_name']
         RGT = int(kwargs['RGT'])
         GT = int(kwargs['GT'])
         # skip plot creation if no values are entered
-        if (RGT == 0):
+        if (RGT == 0) or (GT == 0):
             return
         # create figure axis
         if kwargs['ax'] is None:
@@ -2557,22 +2555,19 @@ def plot(self, **kwargs):
             ax.set_xlabel('Along-Track Distance [m]')
             ax.set_ylabel(f'SlideRule {column}')
         elif (kwargs['kind'] == 'scatter'):
-            # extract pair track parameters
-            LR = int(kwargs['LR'])
-            PT = int(kwargs['PT'])
             # extract orbital cycle parameters
             cycle = int(kwargs['cycle'])
             if (kwargs['atl03'] == 'dataframe'):
                 # reduce entered data frame to RGT, ground track and cycle
                 atl03 = self._gdf[(self._gdf['rgt'] == RGT) &
-                    (self._gdf['track'] == PT) &
-                    (self._gdf['pair'] == LR) &
+                    (self._gdf['track'] == self.PT(GT)) &
+                    (self._gdf['pair'] == self.LR(GT)) &
                     (self._gdf['cycle'] == cycle)]
             elif (kwargs['atl03'] is not None):
                 # reduce ATL03 data frame to RGT, ground track and cycle
                 atl03 = kwargs['atl03'][(kwargs['atl03']['rgt'] == RGT) &
-                    (kwargs['atl03']['track'] == PT) &
-                    (kwargs['atl03']['pair'] == LR) &
+                    (kwargs['atl03']['track'] == self.PT(GT)) &
+                    (kwargs['atl03']['pair'] == self.LR(GT)) &
                     (kwargs['atl03']['cycle'] == cycle)]
             if (kwargs['classification'] == 'atl08'):
                 # noise, ground, canopy, top of canopy, unclassified
@@ -2639,3 +2634,26 @@ def plot(self, **kwargs):
         if kwargs['ax'] is None:
             # show the figure
             plt.tight_layout()
+
+    def ground_track(self, GT):
+        """extract the ground track name for a given Ground Track (GT) index
+        """
+        ground_track_list = ['gt1l', 'gt1r', 'gt2l', 'gt2r', 'gt3l', 'gt3r']
+        return ground_track_list[GT//10 - 1]
+
+    def PT(self, GT):
+        """extract Pair Track (PT) index for a given Ground Track (GT) index
+        """
+        # mapping between ground tracks and sliderule tracks
+        ground_track = self.ground_track(GT)
+        pair_track_dict = dict(gt1l=1,gt1r=1,gt2l=2,gt2r=2,gt3l=3,gt3r=3)
+        return pair_track_dict[ground_track]
+
+    def LR(self, GT):
+        """extract Left-Right (LR) index for a given Ground Track (GT) index
+        """
+        # mapping between ground tracks and sliderule tracks
+        ground_track = self.ground_track(GT)
+        lr_track_dict = dict(gt1l=0,gt1r=1,gt2l=0,gt2r=1,gt3l=0,gt3r=1)
+        return lr_track_dict[ground_track]
+