ThierryO

abuff <- function(spgeom, ratio = 1.1, precision = 0.00001, maxsteps = 20){
    require(rgeos)
    spgeom.area <- gArea(spgeom)
    spgeom.perimeter <- gLength(spgeom)
    buffer.width <- (ratio - 1) * spgeom.area / spgeom.perimeter
    buffered.spgeom <- gBuffer(spgeom, width = buffer.width)
    achieved.precision <- gArea(buffered.spgeom) / spgeom.area - ratio
    
    steps <- 1