I have a spatialPolygons object in R; but I can not to retrieve the "coords" for each spatialPolygon object
Here's my R session:
[[1]]
An object of class "Polygon"
Slot "labpt":
[1] 5.7828 20.5764
Slot "area":
[1] 0.16
Slot "hole":
[1] FALSE
Slot "ringDir":
[1] 1
Slot "coords":
x y
[1,] 5.6828 20.7764
[2,] 5.7828 20.7764
[3,] 5.8828 20.7764
[4,] 5.9828 20.7764
[5,] 5.9828 20.3764
[6,] 5.8828 20.3764
[7,] 5.7828 20.3764
[8,] 5.6828 20.3764
[9,] 5.5828 20.3764
[10,] 5.5828 20.7764
[11,] 5.6828 20.7764
[[2]]
An object of class "Polygon"
Slot "labpt":
[1] 3.715865 35.160271
Slot "area":
[1] 39.68
Slot "hole":
[1] FALSE
Slot "ringDir":
[1] 1
Slot "coords":
x y
[1,] -0.7172 35.1764
[2,] -0.8172 35.1764
[3,] -0.9172 35.1764
[4,] -1.0172 35.1764
[5,] -1.1172 35.1764
[6,] -1.1172 35.5764
[7,] -1.2172 35.5764
[8,] -1.2172 35.9764
[9,] -1.2172 36.3764
[10,] -1.3172 36.3764
[11,] -1.3172 36.7764
[12,] -1.4172 36.7764
[13,] -1.5172 36.7764
[14,] -1.6172 36.7764
[15,] -1.6172 37.1764
[16,] -1.5172 37.1764
[17,] -1.4172 37.1764
[18,] -1.3172 37.1764
[19,] -1.2172 37.1764
[20,] -1.1172 37.1764
[21,] -1.0172 37.1764
[22,] -0.9172 37.1764
[23,] -0.8172 37.1764
[24,] -0.7172 37.1764
[25,] -0.6172 37.1764
[26,] -0.5172 37.1764
[27,] -0.4172 37.1764
[28,] -0.3172 37.1764
[29,] -0.2172 37.1764
[30,] -0.1172 37.1764
[31,] -0.0172 37.1764
[32,] 0.0828 37.1764
[33,] 0.1828 37.1764
[34,] 0.2828 37.1764
[35,] 0.3828 37.1764
[36,] 0.4828 37.1764
[37,] 0.5828 37.1764
[38,] 0.6828 37.1764
[39,] 0.7828 37.1764
[40,] 0.8828 37.1764
[41,] 0.9828 37.1764
[42,] 1.0828 37.1764
[43,] 1.1828 37.1764
[44,] 1.2828 37.1764
[45,] 1.3828 37.1764
[46,] 1.4828 37.1764
[47,] 1.5828 37.1764
[48,] 1.6828 37.1764
[49,] 1.7828 37.1764
[50,] 1.8828 37.1764
[51,] 1.9828 37.1764
[52,] 2.0828 37.1764
[53,] 2.1828 37.1764
[54,] 2.2828 37.1764
[55,] 2.3828 37.1764
[56,] 2.4828 37.1764
[57,] 2.5828 37.1764
[58,] 2.6828 37.1764
[59,] 2.7828 37.1764
[60,] 2.8828 37.1764
[61,] 2.9828 37.1764
[62,] 3.0828 37.1764
[63,] 3.1828 37.1764
[64,] 3.2828 37.1764
[65,] 3.3828 37.1764
[66,] 3.4828 37.1764
[67,] 3.5828 37.1764
[68,] 3.6828 37.1764
[69,] 3.7828 37.1764
[70,] 3.8828 37.1764
[71,] 3.9828 37.1764
[72,] 4.0828 37.1764
[73,] 4.1828 37.1764
[74,] 4.2828 37.1764
[75,] 4.3828 37.1764
[76,] 4.4828 37.1764
[77,] 4.5828 37.1764
[78,] 4.6828 37.1764
[79,] 4.7828 37.1764
[80,] 4.8828 37.1764
[81,] 4.9828 37.1764
[82,] 5.0828 37.1764
[83,] 5.1828 37.1764
[84,] 5.2828 37.1764
[85,] 5.3828 37.1764
[86,] 5.4828 37.1764
[87,] 5.5828 37.1764
[88,] 5.6828 37.1764
[89,] 5.7828 37.1764
[90,] 5.8828 37.1764
[91,] 5.9828 37.1764
[92,] 6.0828 37.1764
[93,] 6.1828 37.1764
[94,] 6.2828 37.1764
[95,] 6.3828 37.1764
[96,] 6.4828 37.1764
[97,] 6.5828 37.1764
[98,] 6.6828 37.1764
[99,] 6.7828 37.1764
[100,] 6.8828 37.1764
[101,] 6.9828 37.1764
[102,] 7.0828 37.1764
[103,] 7.1828 37.1764
[104,] 7.2828 37.1764
[105,] 7.3828 37.1764
[106,] 7.4828 37.1764
[107,] 7.5828 37.1764
[108,] 7.6828 37.1764
[109,] 7.7828 37.1764
[110,] 7.8828 37.1764
[111,] 7.9828 37.1764
[112,] 8.0828 37.1764
[113,] 8.1828 37.1764
[114,] 8.2828 37.1764
[115,] 8.3828 37.1764
[116,] 8.4828 37.1764
[117,] 8.5828 37.1764
[118,] 8.6828 37.1764
[119,] 8.7828 37.1764
[120,] 8.8828 37.1764
[121,] 8.9828 37.1764
[122,] 9.0828 37.1764
[123,] 9.1828 37.1764
[124,] 9.2828 37.1764
[125,] 9.3828 37.1764
[126,] 9.4828 37.1764
[127,] 9.5828 37.1764
[128,] 9.6828 37.1764
[129,] 9.7828 37.1764
[130,] 9.8828 37.1764
[131,] 9.9828 37.1764
[132,] 10.0828 37.1764
[133,] 10.1828 37.1764
[134,] 10.2828 37.1764
[135,] 10.3828 37.1764
[136,] 10.4828 37.1764
[137,] 10.5828 37.1764
[138,] 10.6828 37.1764
[139,] 10.7828 37.1764
[140,] 10.8828 37.1764
[141,] 10.9828 37.1764
[142,] 11.0828 37.1764
[143,] 11.1828 37.1764
[144,] 11.2828 37.1764
[145,] 11.3828 37.1764
[146,] 11.4828 37.1764
[147,] 11.5828 37.1764
[148,] 11.6828 37.1764
[149,] 11.7828 37.1764
[150,] 11.8828 37.1764
[151,] 11.9828 37.1764
[152,] 11.9828 36.7764
[153,] 11.9828 36.3764
[154,] 11.9828 35.9764
[155,] 11.9828 35.5764
[156,] 11.9828 35.1764
[157,] 11.8828 35.1764
[158,] 11.7828 35.1764
[159,] 11.6828 35.1764
[160,] 11.5828 35.1764
[161,] 11.4828 35.1764
[162,] 11.3828 35.1764
[163,] 11.2828 35.1764
[164,] 11.1828 35.1764
[165,] 11.0828 35.1764
[166,] 10.9828 35.1764
[167,] 10.8828 35.1764
[168,] 10.7828 35.1764
[169,] 10.6828 35.1764
[170,] 10.5828 35.1764
[171,] 10.4828 35.1764
[172,] 10.3828 35.1764
[173,] 10.2828 35.1764
[174,] 10.1828 35.1764
[175,] 10.0828 35.1764
[176,] 9.9828 35.1764
[177,] 9.8828 35.1764
[178,] 9.7828 35.1764
[179,] 9.6828 35.1764
[180,] 9.5828 35.1764
[181,] 9.4828 35.1764
[182,] 9.3828 35.1764
[183,] 9.2828 35.1764
[184,] 9.2828 35.5764
[185,] 9.1828 35.5764
[186,] 9.0828 35.5764
[187,] 8.9828 35.5764
[188,] 8.8828 35.5764
[189,] 8.7828 35.5764
[190,] 8.6828 35.5764
[191,] 8.6828 35.9764
[192,] 8.5828 35.9764
[193,] 8.5828 36.3764
[194,] 8.4828 36.3764
[195,] 8.3828 36.3764
[196,] 8.2828 36.3764
[197,] 8.1828 36.3764
[198,] 8.0828 36.3764
[199,] 8.0828 36.7764
[200,] 7.9828 36.7764
[201,] 7.8828 36.7764
[202,] 7.8828 36.3764
[203,] 7.8828 35.9764
[204,] 7.7828 35.9764
[205,] 7.7828 35.5764
[206,] 7.6828 35.5764
[207,] 7.5828 35.5764
[208,] 7.4828 35.5764
[209,] 7.4828 35.1764
[210,] 7.3828 35.1764
[211,] 7.2828 35.1764
[212,] 7.1828 35.1764
[213,] 7.0828 35.1764
[214,] 6.9828 35.1764
[215,] 6.8828 35.1764
[216,] 6.7828 35.1764
[217,] 6.7828 35.5764
[218,] 6.8828 35.5764
[219,] 6.8828 35.9764
[220,] 6.7828 35.9764
[221,] 6.7828 36.3764
[222,] 6.6828 36.3764
[223,] 6.5828 36.3764
[224,] 6.4828 36.3764
[225,] 6.4828 36.7764
[226,] 6.3828 36.7764
[227,] 6.2828 36.7764
[228,] 6.1828 36.7764
[229,] 6.0828 36.7764
[230,] 5.9828 36.7764
[231,] 5.9828 36.3764
[232,] 5.9828 35.9764
[233,] 5.8828 35.9764
[234,] 5.7828 35.9764
[235,] 5.7828 35.5764
[236,] 5.7828 35.1764
[237,] 5.6828 35.1764
[238,] 5.5828 35.1764
[239,] 5.4828 35.1764
[240,] 5.3828 35.1764
[241,] 5.2828 35.1764
[242,] 5.1828 35.1764
[243,] 5.0828 35.1764
[244,] 4.9828 35.1764
[245,] 4.9828 34.7764
[246,] 4.8828 34.7764
[247,] 4.7828 34.7764
[248,] 4.6828 34.7764
[249,] 4.6828 34.3764
[250,] 4.5828 34.3764
[251,] 4.4828 34.3764
[252,] 4.4828 33.9764
[253,] 4.3828 33.9764
[254,] 4.2828 33.9764
[255,] 4.2828 33.5764
[256,] 4.1828 33.5764
[257,] 4.0828 33.5764
[258,] 3.9828 33.5764
[259,] 3.9828 33.1764
[260,] 3.8828 33.1764
[261,] 3.7828 33.1764
[262,] 3.6828 33.1764
[263,] 3.5828 33.1764
[264,] 3.4828 33.1764
[265,] 3.3828 33.1764
[266,] 3.3828 32.7764
[267,] 3.2828 32.7764
[268,] 3.1828 32.7764
[269,] 3.0828 32.7764
[270,] 3.0828 32.3764
[271,] 2.9828 32.3764
[272,] 2.8828 32.3764
[273,] 2.7828 32.3764
[274,] 2.7828 31.9764
[275,] 2.6828 31.9764
[276,] 2.5828 31.9764
[277,] 2.4828 31.9764
[278,] 2.3828 31.9764
[279,] 2.3828 31.5764
[280,] 2.2828 31.5764
[281,] 2.1828 31.5764
[282,] 2.0828 31.5764
[283,] 1.9828 31.5764
[284,] 1.8828 31.5764
[285,] 1.7828 31.5764
[286,] 1.6828 31.5764
[287,] 1.5828 31.5764
[288,] 1.4828 31.5764
[289,] 1.3828 31.5764
[290,] 1.2828 31.5764
[291,] 1.1828 31.5764
[292,] 1.0828 31.5764
[293,] 0.9828 31.5764
[294,] 0.8828 31.5764
[295,] 0.7828 31.5764
[296,] 0.6828 31.5764
[297,] 0.5828 31.5764
[298,] 0.4828 31.5764
[299,] 0.3828 31.5764
[300,] 0.2828 31.5764
[301,] 0.1828 31.5764
[302,] 0.0828 31.5764
[303,] -0.0172 31.5764
[304,] -0.0172 31.9764
[305,] -0.1172 31.9764
[306,] -0.2172 31.9764
[307,] -0.3172 31.9764
[308,] -0.4172 31.9764
[309,] -0.5172 31.9764
[310,] -0.6172 31.9764
[311,] -0.7172 31.9764
[312,] -0.7172 32.3764
[313,] -0.8172 32.3764
[314,] -0.9172 32.3764
[315,] -1.0172 32.3764
[316,] -1.0172 32.7764
[317,] -1.1172 32.7764
[318,] -1.1172 33.1764
[319,] -1.0172 33.1764
[320,] -1.0172 33.5764
[321,] -0.9172 33.5764
[322,] -0.8172 33.5764
[323,] -0.8172 33.9764
[324,] -0.7172 33.9764
[325,] -0.6172 33.9764
[326,] -0.5172 33.9764
[327,] -0.4172 33.9764
[328,] -0.3172 33.9764
[329,] -0.3172 34.3764
[330,] -0.2172 34.3764
[331,] -0.2172 34.7764
[332,] -0.3172 34.7764
[333,] -0.4172 34.7764
[334,] -0.5172 34.7764
[335,] -0.5172 35.1764
[336,] -0.6172 35.1764
[337,] -0.7172 35.1764
[[3]]
An object of class "Polygon"
Slot "labpt":
[1] 1.199467 36.200642
Slot "area":
[1] 1.32
Slot "hole":
[1] TRUE
Slot "ringDir":
[1] -1
Slot "coords":
x y
[1,] 0.7828 35.5764
[2,] 0.8828 35.5764
[3,] 0.9828 35.5764
[4,] 1.0828 35.5764
[5,] 1.1828 35.5764
[6,] 1.2828 35.5764
[7,] 1.3828 35.5764
[8,] 1.4828 35.5764
[9,] 1.5828 35.5764
[10,] 1.6828 35.5764
[11,] 1.6828 35.9764
[12,] 1.7828 35.9764
[13,] 1.8828 35.9764
[14,] 1.8828 36.3764
[15,] 1.7828 36.3764
[16,] 1.6828 36.3764
[17,] 1.6828 36.7764
[18,] 1.5828 36.7764
[19,] 1.4828 36.7764
[20,] 1.3828 36.7764
[21,] 1.2828 36.7764
[22,] 1.1828 36.7764
[23,] 1.0828 36.7764
[24,] 0.9828 36.7764
[25,] 0.8828 36.7764
[26,] 0.7828 36.7764
[27,] 0.6828 36.7764
[28,] 0.5828 36.7764
[29,] 0.5828 36.3764
[30,] 0.5828 35.9764
[31,] 0.6828 35.9764
[32,] 0.7828 35.9764
[33,] 0.7828 35.5764
[[4]]
An object of class "Polygon"
Slot "labpt":
[1] 2.8828 33.6164
Slot "area":
[1] 0.4
Slot "hole":
[1] TRUE
Slot "ringDir":
[1] -1
Slot "coords":
x y
[1,] 2.5828 33.9764
[2,] 2.5828 33.5764
[3,] 2.6828 33.5764
[4,] 2.6828 33.1764
[5,] 2.7828 33.1764
[6,] 2.8828 33.1764
[7,] 2.9828 33.1764
[8,] 3.0828 33.1764
[9,] 3.0828 33.5764
[10,] 3.1828 33.5764
[11,] 3.1828 33.9764
[12,] 3.0828 33.9764
[13,] 2.9828 33.9764
[14,] 2.8828 33.9764
[15,] 2.7828 33.9764
[16,] 2.6828 33.9764
[17,] 2.5828 33.9764
so I want to extract the Slot "coords" from [[1]] in a dataframe ,Slot "coords" from[[2]] in another dataframe so on...
can someone help me please?
edit :
for example, as extracting coordinates???
[1,] 5.6828 20.7764
[2,] 5.7828 20.7764
[3,] 5.8828 20.7764
[4,] 5.9828 20.7764
[5,] 5.9828 20.3764
[6,] 5.8828 20.3764
[7,] 5.7828 20.3764
[8,] 5.6828 20.3764
[9,] 5.5828 20.3764
[10,] 5.5828 20.7764
[11,] 5.6828 20.7764
A SpatialPolygons object is a list of polygons, each of which is a list of Polygons (yes, the only difference is in the capitalization...). The latter has the coordinates.
Here is an example of provinces in France, downloaded from GADM:
library(raster)
FR <- getData('GADM',country='FRA',level=1)
length(FR@polygons)
# [1] 22
sapply(FR@polygons,function(p)length(p@Polygons))
# [1] 1 1 1 2 1 28 2 2 1 1 2 16 245 10 11 3 1 2 1 8 28 23
So FR is a spatialPolygons object representing French provinces. There are 22 polygons representing the provinces, and each of these has one or more Polygons containing the physical coordinates (e.g., lat and long) of the boundary. There can be multiple Polygons because the geographies can be dis-contiguous (e.g. islands, etc.). In fact the land-locked provinces generally have just one Polygon, whereas the coastal provinces have many.
So do you want 22 data frames, one for each province, or you so want a dataframe for each geography?
If you know that your spatiaPolygons object has only one Polygon for each polygon, then you could do it this way:
result <- lapply(FR@polygons,function(p) data.frame(p@Polygons[[1]]@coords))
In this case I'm just grabbing the coordinates of the first Polygon in each province.