r - 更改 SpatialLinesDataFrame 坐标以适应 shapefile

Question

我有马拉维街道的 SpatialLinesDataFrame 和马拉维国家的 Shapefile。问题是其中一条街道的某些部分的坐标位于马拉维湖中（这在现实中显然是不可能的），所以我认为shapefile和SpatialLinesDataFrame之间存在一些问题。如何更正 SpatialLinesDataFrame 的坐标，以便它们可以正确重叠？我用于马拉维的 shapefile 可以在这里找到：mwi_adm_nso_20181016_SHP.zip（我使用的文件的名称是 mwi_admbnda_adm3_nso_20181016.shp）。

这里是创建在湖中有路段的街道的 SpatialLinesDataframe 的代码。

# download the shapefile of Malawi
mySHPM <-
  shapefile(
    paste(
      path,
      "/mwi_admbnda_adm3_nso_20181016.shp",
      sep = ""
    )
  )
# subset to focus on the area where the street is
mySHP <- mySHPM[mySHPM$ADM2_EN %in% c("Karonga", "Rumphi"), ]

# define the SpatialLinesDataframe for the street that goes in the lake
Xline <- c(34.21031,34.21031,34.21027,34.21026,34.21023,34.21022,34.21006,34.20951,34.20848,34.20763,
           34.20712,34.20624,34.20524,34.20443,34.20412,34.20409,34.20409,34.20421,34.20418,34.20414, 
           34.20403,34.20437,34.20503,34.20548,34.20598,34.20625,34.20589,34.20493,34.20467,34.20449,
           34.20376,34.20349,34.20377,34.20444,34.20598,34.20694,34.20912,34.20978,34.20999,34.20985,
           34.20950,34.20864,34.20822,34.20820,34.20838,34.20890,34.20905,34.20876,34.20798,34.20697, 
           34.20599,34.20399,34.20219,34.20074,34.19889,34.19631,34.19428,34.19126,34.18883,34.18757, 
           34.18614,34.18343,34.18179,34.17895,34.17602,34.17429,34.17208,34.17101,34.16972,34.16955, 
           34.16949,34.16944,34.16954,34.16986,34.16973,34.16935,34.16908,34.16896,34.16874,34.16783, 
           34.16684,34.16574,34.16509,34.16471,34.16463,34.16445,34.16422,34.16420,34.16399,34.16386,
           34.16358,34.16319,34.16275,34.16217,34.16153,34.16145,34.16154,34.16207,34.16210,34.16196, 
           34.16145,34.16095,34.16044,34.15993,34.15940,34.15889,34.15835,34.15780,34.15720,34.15652, 
           34.15592,34.15546,34.15524,34.15497,34.15463,34.15426,34.15387,34.15335,34.15306,34.15270,
           34.15222,34.15185,34.15141,34.15107,34.15080,34.15071,34.15080,34.15120,34.15137,34.15167,
           34.15143,34.15091,34.15038,34.14988,34.14946,34.14922,34.14899,34.14851,34.14815,34.14800,
           34.14762,34.14732,34.14697,34.14715,34.14691,34.14640,34.14608,34.14568,34.14541,34.14543,
           34.14590,34.14617,34.14634,34.14649,34.14670,34.14647,34.14623,34.14614,34.14628,34.14649,
           34.14633,34.14608,34.14591,34.14556,34.14515,34.14494,34.14472,34.14444,34.14414,34.14378, 
           34.14354,34.14322,34.14309,34.14320,34.14355,34.14380,34.14419,34.14451,34.14485,34.14522,
           34.14538,34.14530,34.14525,34.14522,34.14522,34.14520,34.14521,34.14487,34.14455,34.14419,
           34.14378,34.14341,34.14304,34.14306,34.14355,34.14411,34.14461,34.14485,34.14480,34.14468,
           34.14448,34.14448,34.14438,34.14445,34.14449,34.14443,34.14419,34.14395,34.14341,34.14293,
           34.14259,34.14268,34.14319,34.14367,34.14371,34.14401,34.14402,34.14379,34.14326,34.14281,
           34.14225,34.14182,34.14130,34.14082,34.14021,34.14002,34.13975,34.13975,34.14023,34.14068,
           34.14111,34.14147,34.14145,34.14144,34.14097,34.14035,34.13982,34.13912,34.13863,34.13819, 
           34.13769,34.13761,34.13751,34.13746,34.13699,34.13661,34.13670,34.13716,34.13736,34.13718,
           34.13663,34.13655,34.13655,34.13662,34.13683,34.13707,34.13728,34.13741,34.13740,34.13761,
           34.13824,34.13843,34.13842,34.13796,34.13723,34.13716,34.13718,34.13709,34.13689,34.13702, 
           34.13744,34.13761,34.13754,34.13755,34.13722,34.13682,34.13665,34.13634,34.13631,34.13623,
           34.13625,34.13639,34.13652,34.13656,34.13695,34.13717,34.13716,34.13694,34.13683,34.13632,
           34.13584,34.13532,34.13487,34.13437,34.13384,34.13348,34.13303,34.13258,34.13235,34.13206,
           34.13204,34.13173,34.13134,34.13130,34.13102,34.13098,34.13089,34.13066,34.13052,34.13049,
           34.13005,34.13001,34.12955,34.12952,34.12938,34.12859,34.12828,34.12784,34.12704,34.12610,
           34.12483,34.12405,34.12284,34.12198,34.12105,34.11939,34.11927,34.11853,34.11828,34.11751, 
           34.11658,34.11550,34.11403,34.11364,34.11339,34.11303,34.11240,34.11173,34.11087,34.11034,
           34.10987,34.10982,34.11021,34.11024,34.11016,34.10976,34.10923,34.10895,34.10898,34.10904,
           34.10887,34.10870,34.10847,34.10803,34.10774,34.10691,34.10652,34.10620,34.10544,34.10540,
           34.10547,34.10630,34.10641,34.10682,34.10677,34.10665,34.10664,34.10727,34.10819,34.10943,
           34.11040,34.11054,34.11062,34.11087,34.11081,34.11079,34.11079)


Yline <-
c(-10.45258, -10.45259, -10.45294, -10.45369, -10.45489, -10.45648, -10.45859, -10.46091, -10.46452, -10.46747,
-10.46972, -10.47282, -10.47625, -10.47942, -10.48181, -10.48305, -10.48489, -10.48688, -10.49033, -10.49375,
-10.49606, -10.49860, -10.50286, -10.50589, -10.50926, -10.51182, -10.51374, -10.51642, -10.51806, -10.52037,
-10.52250, -10.52405, -10.52527, -10.52634, -10.52831, -10.52905, -10.53041, -10.53148, -10.53272, -10.53478,
-10.53576, -10.53710, -10.53811, -10.53825, -10.53968, -10.54224, -10.54315, -10.54454, -10.54563, -10.54692,
-10.54783, -10.54895, -10.54994, -10.55071, -10.55176, -10.55325, -10.55491, -10.55747, -10.55951, -10.56054, 
-10.56163, -10.56337, -10.56472, -10.56799, -10.57132, -10.57269, -10.57448, -10.57609, -10.57886, -10.58046,
-10.58276, -10.58438, -10.58613, -10.58850, -10.59053, -10.59210, -10.59307, -10.59355, -10.59357, -10.59333,
-10.59312, -10.59287, -10.59279, -10.59252, -10.59238, -10.59253, -10.59336, -10.59393, -10.59408, -10.59396,
-10.59353, -10.59313, -10.59288, -10.59271, -10.59255, -10.59260, -10.59274, -10.59306, -10.59316, -10.59317,
-10.59296, -10.59305, -10.59316, -10.59342, -10.59353, -10.59358, -10.59341, -10.59330, -10.59337, -10.59367,
-10.59402, -10.59435, -10.59463, -10.59494, -10.59532, -10.59560, -10.59559, -10.59548, -10.59519, -10.59497,
-10.59484, -10.59461, -10.59478, -10.59503, -10.59486, -10.59503, -10.59509, -10.59530, -10.59564, -10.59584,
-10.59583, -10.59578, -10.59600, -10.59620, -10.59639, -10.59614, -10.59587, -10.59588, -10.59584, -10.59549,
-10.59499, -10.59452, -10.59414, -10.59381, -10.59365, -10.59368, -10.59346, -10.59331, -10.59317, -10.59330,
-10.59354, -10.59390, -10.59430, -10.59461, -10.59489, -10.59503, -10.59519, -10.59505, -10.59496, -10.59479,
-10.59466, -10.59449, -10.59425, -10.59387, -10.59365, -10.59346, -10.59352, -10.59341, -10.59355, -10.59355,
-10.59316, -10.59312, -10.59314, -10.59323, -10.59332, -10.59374, -10.59384, -10.59372, -10.59391, -10.59422,
-10.59455, -10.59488, -10.59493, -10.59490, -10.59490, -10.59477, -10.59437, -10.59416, -10.59399, -10.59421,
-10.59427, -10.59405, -10.59378, -10.59391, -10.59426, -10.59459, -10.59435, -10.59452, -10.59462, -10.59500,
-10.59540, -10.59564, -10.59566, -10.59519, -10.59477, -10.59469, -10.59481, -10.59492, -10.59478, -10.59458,
-10.59454, -10.59468, -10.59489, -10.59522, -10.59558, -10.59608, -10.59612, -10.59612, -10.59556, -10.59541,
-10.59550, -10.59559, -10.59540, -10.59518, -10.59522, -10.59529, -10.59534, -10.59547, -10.59551, -10.59564,
-10.59592, -10.59610, -10.59623, -10.59621, -10.59598, -10.59587, -10.59586, -10.59580, -10.59568, -10.59572,
-10.59554, -10.59546, -10.59492, -10.59453, -10.59403, -10.59389, -10.59357, -10.59333, -10.59308, -10.59286,
-10.59283, -10.59279, -10.59239, -10.59197, -10.59184, -10.59131, -10.59120, -10.59101, -10.59062, -10.59048,
-10.59021, -10.59022, -10.59011, -10.59019, -10.59054, -10.59093, -10.59098, -10.59106, -10.59102, -10.59058,
-10.59023, -10.59009, -10.59001, -10.59002, -10.59028, -10.59057, -10.59101, -10.59129, -10.59150, -10.59152,
-10.59151, -10.59108, -10.59072, -10.59039, -10.59010, -10.58976, -10.58972, -10.58904, -10.58882, -10.58845,
-10.58838, -10.58833, -10.58859, -10.58851, -10.58845, -10.58817, -10.58790, -10.58771, -10.58768, -10.58799,
-10.58799, -10.58738, -10.58720, -10.58723, -10.58757, -10.58774, -10.58812, -10.58875, -10.58917, -10.58920,
-10.58930, -10.58927, -10.58915, -10.58919, -10.58933, -10.58968, -10.58981, -10.58970, -10.58913, -10.58871,
-10.58863, -10.58875, -10.58869, -10.58857, -10.58840, -10.58776, -10.58771, -10.58709, -10.58688, -10.58693,
-10.58698, -10.58680, -10.58643, -10.58626, -10.58621, -10.58628, -10.58687, -10.58748, -10.58799, -10.58860,
-10.58908, -10.58929, -10.59015, -10.59142, -10.59176, -10.59204, -10.59191, -10.59216, -10.59234, -10.59253,
-10.59294, -10.59297, -10.59298, -10.59285, -10.59288, -10.59313, -10.59308, -10.59325, -10.59455, -10.59463,
-10.59521, -10.59622, -10.59643, -10.59773, -10.59809, -10.59836, -10.59890, -10.60086, -10.60199, -10.60337,
-10.60447, -10.60461, -10.60458, -10.60432, -10.60430, -10.60432, -10.60433)
 

coords <- as.data.frame(cbind(x = Xline, y = Yline))
Slo1 <- Line(coords)

Sli1 <- Lines(list(Slo1),ID="ID")
HMline <- SpatialLines(list(Sli1))
class(HMline)
proj4string(HMline) <- proj4string(mySHP)
plot(mySHP)
plot(HMline, add = T, col = "red")
# you can notice a small segment going outside the shapefile. if you can't, look at this:

# crop the street to save in "cropped" just the segments that are not overlapping the shapefile
cropped <- gDifference(HMline, mySHP)
plot(HMline)
plot(cropped, add = T, col = "red", lwd = 4)

谢谢你的帮助！

标签： rgeospatial