paths: lists of data.frames containing positions, times, and covariate for each individual
coord: two-vector of character strings giving names of x and y coordinates in data.frames
Time.name: character string giving name of time variable in data.frames
time.grid: grid of possible times to use for interpolation (individuals will only be interpolated to times within the range of observation times)
s_args: List of arguments to mgcv::s() the same length as number of unique individuals. Each entry in the list should be a named list/vector.
uncertainty.type: State what type of uncertainty plot 1 is default for tails more than 1 is amount of predicted trajectories for each unique individual and blurs for blur plot
verbose: logical; TRUE prints messages about fitting details