Smooth the surface of a bullet
bulletSmooth(data, span = 0.03, limits = c(-5, 5), id = "bullet")
| data | data frame as returned by the function   | 
    
|---|---|
| span | width of the smoother, defaults to 0.03  | 
    
| limits | vector of the form c(min, max). Results will be limited to be between these values.  | 
    
| id | variable name of the land identifier  | 
    
data frame of the same form as the input extended by the vector l30 for the smooth.