problems with read.gwt2nb function

Wed, Apr 18, 2007 12:18 PM

On Wed, 18 Apr 2007, Antonio Ramos wrote:

I think this gets you there - you have to give the IDs as the region.id=
argument, otherwise the function is looking for a sequence 1:417:

ba0 <- read.table("ba.GWT", header=FALSE, skip=1)
str(ba0)
ID_ <- unique(ba0$V1)
ba <- read.gwt2nb("ba.GWT", region.id=ID_)
ba

Roger


I already did it but it seems there is similar problems:

?read.gwt2nb
data(baltimore)
STATION <- baltimore$STATION
gwt1 <- read.gwt2nb(system.file("etc/weights/baltk4.GWT",

package="spdep")[1],
+  STATION)
Warning message:
102, 115, 208 are not destinations in:
read.gwt2nb(system.file("etc/weights/baltk4.GWT",
package = "spdep")[1],

cat(paste("Neighbours list symmetry;", is.symmetric.nb(gwt1, FALSE, TRUE),

+  "\n"))
Neighbours list symmetry; FALSE

listw1 <- nb2listw(gwt1, style="B", glist=attr(gwt1, "GeoDa")$dist)
tmpGWT <- tempfile()
write.sn2gwt(listw2sn(listw1), tmpGWT)
gwt2 <- read.gwt2nb(tmpGWT, STATION)

Warning message:
102, 115, 208 are not destinations in: read.gwt2nb(tmpGWT, STATION)

cat(paste("Neighbours list symmetry;", is.symmetric.nb(gwt2, FALSE, TRUE),

+  "\n"))
Neighbours list symmetry; FALSE

diffnb(gwt1, gwt2)

Neighbour list object:
Number of regions: 211
Number of nonzero links: 0
Percentage nonzero weights: 0
Average number of links: 0
211 regions with no links:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53
54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78
79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102
103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121
122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140
141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159
160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178
179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197
198 199 200 201 202 203 204 205 206 207 208 209 210 211

data(oldcol)
tmpMAT <- tempfile()



If you do not see the same issues there, you

will need to look carefully at your GWT file, which may not be what you
think.It is a text file, so is easy to examine. Please also try to
provide access to the GWT file, if you think that it does contain what you
think.

I also did it but I see no problem with my gwt file (made via Geoda):

0 417 ba_base_toda ID_
291110 290320         1.14838787
291110 292620         1.20007809
291110 292840         1.26206315
291110 291955         1.39205921
291110 290140         1.54464659
291110 292045          1.7405391
291110 290740         1.81707945
291110 290940         1.83009167
290320 292620        0.466408625
290320 291955        0.650969045
290320 290140        0.757652243
290320 290740        0.890575291
290320 292890        0.912077132

 Attached to this email there is the whole file.

At least some regions seem to have no neighbours.


Since I use the option k-nearest neighbors in GeoDa, it is impossible there
is regions without neighbours in this .gwt file.

Any second thoughts?

Help and advice really appreciated,

Antonio.

Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no

problems with read.gwt2nb function

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