


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
info@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
 

 		 	   		  
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