[R-sig-Geo] problems with read.gwt2nb function

[Roger Bivand]

On Wed, 18 Apr 2007, Antonio Ramos wrote:

> Hi Roger,
> 
> 
> I believe that you should pay attention to the warning. Please run the
> > example for the function.

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