1. 2012-05-29 Re: [R-sig-Geo] zero cost in gdistance r-sig-geo karljarvis 2. 2012-05-29 Re: [R-sig-Geo] zero cost in gdistance r-sig-geo Jacob van Etten 3. 2012-05-29 [R-sig-Geo] zero cost in gdistance r-sig-geo karljarvis