l_getPlots.l_tour       Query a loon widget
l_getProjection         Query the matrix of projection vectors
l_layer_callback        Tour Layer Configuration
l_layer_density2d       2D density layer
l_layer_hull            Layer a hull for 'loon'
l_layer_trails          Display tour path with trails
l_tour                  Tour in loon
tour_pairs              Tour Pairs Plot
