Generalize for absent fields cyclone or valid

This occurs when we read results from the Matlab program.

Analysis/plot_eddy_contours.py

@@ -75,17 +75,21 @@ def snapshot(ax, ishape_list, readers, *, dashed = False, light = False,
 
         points = shape_rec_extr.shape.points[0]
 
-        if shape_rec_extr.record.cyclone == 0:
-                # Anti-cyclone
-            color = "red"
+        if "cyclone" in shape_rec_extr.record:
+            if shape_rec_extr.record.cyclone == 0:
+                    # Anti-cyclone
+                color = "red"
+            else:
+                color = "blue"
         else:
-            color = "blue"
+            color = "green"
 
         lines = ax.plot(points[0], points[1], markersize = 10,
                         color = color, fillstyle = "none",
                         transform = src_crs)
 
-        if shape_rec_extr.record.valid == 1:
+        if "valid" not in shape_rec_extr.record \
+           or shape_rec_extr.record.valid == 1:
             if light:
                 lines[0].set_marker("+")
             else:
@@ -107,7 +111,8 @@ def snapshot(ax, ishape_list, readers, *, dashed = False, light = False,
                             transform = src_crs)
 
             if not light:
-                if shape_rec_extr.record.valid == 0:
+                if "valid" in shape_rec_extr.record \
+                   and shape_rec_extr.record.valid == 0:
                     # Invalid outermost contour
                     lines[0].set_marker("s")
                     lines[0].set_fillstyle("none")
@@ -122,11 +127,14 @@ def snapshot(ax, ishape_list, readers, *, dashed = False, light = False,
             if shape_m_s != None and shape_m_s.shapeType != shapefile.NULL:
                 points = np.array(shape_m_s.points)
 
-                if shape_rec_extr.record.cyclone == 0:
-                    # Anti-cyclone
-                    color = "magenta"
+                if "cyclone" in shape_rec_extr.record:
+                    if shape_rec_extr.record.cyclone == 0:
+                        # Anti-cyclone
+                        color = "magenta"
+                    else:
+                        color = "cyan"
                 else:
-                    color = "cyan"
+                    color = "green"
 
                 lines = ax.plot(points[:, 0], points[:, 1], color = color,
                                 transform = src_crs)