There is a difference between visual perception of points being on a grid, and the numerical confirmation of this.
Have you tried grid_new <- points2grid(SpatialPoints(coord_nficentroid), tolerance= 0.41, round=NULL, fuzz.tol=3) as the message sugggested? On 11/02/2010 03:03 AM, Yan Boulanger wrote: > > > > Hi > everyone, > > > > This seems > (again) a very simple question but I’m not able to get this work. I have point > data from the Canadian National Forest Inventory. This inventory was realized > using a grid of 20 regularly spaced points. Even though I have access to the > point data, I don’t have the grid data. Actually, I would like to use the grid > data in order to do some moving window analyses. Plotting the point makes it > obvious that these were generated using a grid. I used the points2grid in > order > to convert Grid. However, I get this error message : > > > > library(rgdal) > > nfi_centroid > <- readOGR(".", "nbie") > > coord_nficentroid<-coordinates(nfi_centroid) > > grid_new > <- points2grid(SpatialPoints(coord_nficentroid), > tolerance=sqrt(.Machine$double.eps), round=NULL, fuzz.tol=3) > > > > suggested > tolerance minimum: 0.40961317562634 > > Erreur dans > points2grid(SpatialPoints(coord_nficentroid), tolerance = > sqrt(.Machine$double.eps), : > > dimension 1 : coordinate intervals are not > constant > > > > However, > one could see that intervals are constant except, of course, when points fall > in water. I tried with a subset of points that excluded any point skipping due > to water and got that same result. I’m a little bit puzzled… I’m surely > missing > something! > > > > Thanks for > the help! > > > > Yan > > > > Using R > 2.11.1 > > > > The original > projection was : > > Projected > Coordinate System: NAD_1983_Albers > > Projection: > Albers > > False_Easting: > 0,00000000 > > False_Northing: > 0,00000000 > > Central_Meridian: > -95,00000000 > > Standard_Parallel_1: > 49,00000000 > > Standard_Parallel_2: > 77,00000000 > > Latitude_Of_Origin: > 49,00000000 > > Linear > Unit: Meter > > > > Geographic > Coordinate System: GCS_North_American_1983 > > Datum: > D_North_American_1983 > > Prime > Meridian: Greenwich > > Angular > Unit: Degree > > > > Here’s > a subset of the point data for New Brunswick. > > coordinates Id > > 1 (2200320, 384479) 0 > > 2 (2192230, 366274) 0 > > 3 (2095010, 343514) 0 > > 4 (2165910, 356022) 0 > > 5 (2076780, 351499) 0 > > 6 (2184140, 348078) 0 > > 7 (2202370, 340149) 0 > > 8 (2157810, 337828) 0 > > 9 (2113240, 335544) 0 > > 10 (2149700, 319642) 0 > > 11 (2068680, 333298) 0 > > 12 (2176040, 329890) 0 > > 13 (2131470, 327586) 0 > > 14 (2105140, 317356) 0 > > 15 (2060570, 315108) 0 > > 16 (2167930, 311709) 0 > > 17 (2086910, 325320) 0 > > 18 (2194270, 321966) 0 > > 19 (2042340, 323093) 0 > > 20 (2078790, 307135) 0 > > 21 (2186160, 303791) 0 > > 22 (2123360, 309404) 0 > > 23 (2159810, 293539) 0 > > 24 (1981530, 284526) 0 > > 25 (2034220, 304904) 0 > > 26 (2141590, 301465) 0 > > 27 (1989650, 302709) 0 > > 28 (2222600, 287994) 0 > > 29 (2070670, 288956) 0 > > 30 (2097020, 299175) 0 > > 31 (2052450, 296924) 0 > > 32 (2007870, 294710) 0 > > 33 (2115250, 291229) 0 > > 34 (2088900, 281003) 0 > > 35 (2151690, 275374) 0 > > 36 (1963300, 292533) 0 > > 37 (2178040, 285625) 0 > > 38 (2026100, 286723) 0 > > 39 (1973390, 266350) 0 > > 40 (2206340, 251692) 0 > > 41 (2133470, 283295) 0 > > 42 (2169910, 267467) 0 > > 43 (2017970, 268551) 0 > > 44 (2196260, 277725) 0 > > 45 (2044320, 278750) 0 > > 46 (1999750, 276532) 0 > > 47 (2188130, 259573) 0 > > 48 (2036190, 260582) 0 > > 49 (2054410, 252625) 0 > > 50 (2107120, 273062) 0 > > 51 (1955170, 274350) 0 > > 52 (2214470, 269839) 0 > > 53 (2062550, 270788) 0 > > 54 (2125340, 265134) 0 > > 55 (2143560, 257219) 0 > > 56 (1991610, 258362) 0 > > 57 (2232690, 261965) 0 > > 58 (2080770, 262838) 0 > > 59 (2250900, 254106) 0 > > 60 (1965250, 248184) 0 > > 61 (2224550, 243825) 0 > > 62 (2072630, 244684) 0 > > 63 (2098990, 254904) 0 > > 64 (2109060, 228836) 0 > > 65 (2161770, 249317) 0 > > 66 (2009830, 250387) 0 > > 67 (2269110, 246260) 0 > > 68 (2117200, 246982) 0 > > 69 (2331860, 240924) 0 > > 70 (2179990, 241429) 0 > > 71 (2028050, 242424) 0 > > 72 (2135420, 239072) 0 > > 73 (1983470, 240202) 0 > > 74 (2242760, 235970) 0 > > 75 (2090840, 236753) 0 > > 76 (2198200, 233554) 0 > > 77 (2046270, 234474) 0 > > 78 (2305520, 230608) 0 > > 79 (2260960, 228130) 0 > > 80 (1957100, 230026) 0 > > 81 (2234610, 217843) 0 > > 82 (2315560, 204691) 0 > > 83 (2163690, 205166) 0 > > 84 (2216410, 225692) 0 > > 85 (2064480, 226536) 0 > > 86 (2323720, 222803) 0 > > 87 (2171840, 223293) 0 > > 88 (2019900, 224274) 0 > > 89 (2279170, 220303) 0 > > 90 (2153630, 231176) 0 > > 91 (2001690, 232232) 0 > > 92 (2100910, 210701) 0 > > 93 (1948950, 211877) 0 > > 94 (2127270, 220933) 0 > > 95 (1975320, 222049) 0 > > 96 (2082690, 218612) 0 > > 97 (2190050, 215424) 0 > > 98 (2038110, 216330) 0 > > 99 (2297370, 212490) 0 > > 100 (2145480, 213043) 0 > > 101 (2252810, 210010) 0 > > 102 (2208250, 207567) 0 > > 103 (2056330, 208398) 0 > > 104 (2165550, 161088) 0 > > 105 (2281040, 176281) 0 > > 106 (2129150, 176804) 0 > > 107 (2272870, 158190) 0 > > 108 (2271010, 202188) 0 > > 109 (2119110, 202803) 0 > > 110 (2074540, 200480) 0 > > 111 (2226450, 199725) 0 > > 112 (2066370, 182357) 0 > > 113 (2147350, 168939) 0 > > 114 (2254680, 165986) 0 > > 115 (2181890, 197303) 0 > > 116 (2029960, 198195) 0 > > 117 (2289210, 194380) 0 > > 118 (2137320, 194919) 0 > > 119 (2244650, 191898) 0 > > 120 (2092740, 192575) 0 > > 121 (1940780, 193737) 0 > > 122 (2200090, 189452) 0 > > 123 (2048160, 190269) 0 > > 124 (2155520, 187049) 0 > > 125 (2262850, 184082) 0 > > 126 (2110950, 184683) 0 > > 127 (2218290, 181616) 0 > > 128 (2173720, 179191) 0 > > 129 (2120980, 158699) 0 > > 130 (2236480, 173795) 0 > > 131 (2084580, 174458) 0 > > 132 (2191920, 171347) 0 > > 133 (2039990, 172149) 0 > > 134 (2299230, 168494) 0 > > 135 (2102780, 166572) 0 > > 136 (2210120, 163517) 0 > > 137 (2058200, 164243) 0 > > 138 (2228310, 155700) 0 > > 139 (2094600, 148470) 0 > > 140 (2076400, 156350) 0 > > 141 (2220130, 137616) 0 > > 142 (2068220, 138252) 0 > > 143 (2183750, 153250) 0 > > 144 (2112800, 140604) 0 > > 145 (2139170, 150840) 0 > > 146 (2246500, 147898) 0 > > 147 (2201940, 145427) 0 > > 148 (2050020, 146139) 0 > > 149 (2157370, 142996) 0 > > 150 (2264680, 140109) 0 > > 151 (2193750, 127345) 0 > > 152 (2203740, 101476) 0 > > 153 (2175560, 135164) 0 > > 154 (2130990, 132751) 0 > > 155 (2238310, 129820) 0 > > 156 (2086410, 130378) 0 > > 157 (2149180, 124911) 0 > > 158 (2256490, 122037) 0 > > 159 (2104610, 122518) 0 > > 160 (2211930, 119542) 0 > > 161 (2060020, 120164) 0 > > 162 (2167370, 117086) 0 > > 163 (2122800, 114671) 0 > > 164 (2230120, 111751) 0 > > 165 (2078220, 112296) 0 > > 166 (2187320, 65377.6) 0 > > 167 (2160920, 55121.2) 0 > > 168 (2185550, 109274) 0 > > 169 (2140980, 106838) 0 > > 170 (2248300, 103974) 0 > > 171 (2096410, 104442) 0 > > 172 (2240090, 85921.7) 0 > > 173 (2088200, 86376) 0 > > 174 (2124570, 70720.6) 0 > > 175 (2159170, 99019) 0 > > 176 (2114600, 96602.2) 0 > > 177 (2221920, 93691.9) 0 > > 178 (2070010, 94223.2) 0 > > 179 (2177350, 91213.9) 0 > > 180 (2132780, 88774.2) 0 > > 181 (2195530, 83422.5) 0 > > 182 (2150960, 80962.3) 0 > > 183 (2106390, 78541.3) 0 > > 184 (2213710, 75643.1) 0 > > 185 (2169140, 73162.6) 0 > > 186 (2205490, 57605.4) 0 > > 187 (2079990, 68319) 0 > > 188 (2142750, 62914.6) 0 > > 189 (2116350, 52677.1) 0 > > 190 (2179100, 47343.4) 0 > > 191 (2134520, 44877.3) 0 > > 192 (2170870, 29318.1) 0 > > 193 (2152700, 37090.6) 0 > > 194 > (2198950, -4186.01) 0 > > > > Yan Boulanger > Dendrolab - Datation de bâtiments patrimoniaux par dendrochronologie > www.dendrolab.ca > i...@dendrolab.ca > > > > Université du Québec à Rimouski > Département de Biologie > Centre d'études nordiques > 300, allée des Ursulines > Rimouski, PQ G5L 3A1 > (418) 723-1986 poste 1482 > > > > [[alternative HTML version deleted]] > > > > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Edzer Pebesma Institute for Geoinformatics (ifgi), University of Münster Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de http://www.52north.org/geostatistics e.pebe...@wwu.de _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo