animate_paths           animate paths
blur_point              blur ellipses function
check_overwrite         Check overwrite
covariate_interp        Synchronous interpolation of covariate using
                        either GAM (same as paths) or piece-wise
                        constant if covariate is a factor
gam_interp              GAM interpolation using 'mgcv:gam()'.
get_googlemap_min_scale
                        Figure out scale and centering of google map by
                        transforming reported lat long bounding box
                        back to web mercator
googlemap_proj          adjust center + scale for google map plotting
network_interp          Synchronous interpolation of network using
                        piece-wise constant interpolation
new_alpha               Get good alpha_mult
paths_gam_interp        Synchronous GAM interpolation of all paths
plot.paths_animation    Plot animation path interpolation
vultures                GPS locations of turkey vultures.
whales                  GPS locations of three species of whales.
