[R] data.frame to shape

[Gabor Grothendieck]

Try this:

DF[unlist(tapply(rownames(DF), DF$id, function(x) c(x, x[1]))),]


On 8/9/06, Leonardo Lami <lami at faunalia.it> wrote:
> Hi all,
> I have a simple question:
> I have a data.frame like this:
>
>   id       x       y
> 1  50 1647685 4815259
> 2  50 1647546 4815196
> 3  50 1647454 4815294
> 4  50 1647405 4815347
> 5  50 1647292 4815552
> 6 50 1647737 4815410
> 7 74 1647555 4815201
> 8 74 1647464 4815023
> 9 74 1646970 4815129
> 10 74 1646895 4815264
> 11 74 1646762 4815513
>
> and I'd like to trasform it with the "convert.to.shapefile" function
> (shapefiles package) but to make this I must have a data.frame like this:
>
>   id       x       y
> 1  50 1647685 4815259
> 2  50 1647546 4815196
> 3  50 1647454 4815294
> 4  50 1647405 4815347
> 5  50 1647292 4815552
> 6  50 1647737 4815410
> 7  50 1647685 4815259
> 8  74 1647555 4815201
> 9  74 1647464 4815023
> 10 74 1646970 4815129
> 11 74 1646895 4815264
> 12 74 1646762 4815513
> 13 74 1646762 4815513
>
> with the first point of every id repeated to close the polygon.
> There is a function to make this indipendently by the number of the id
>
> Best regards
> Leonardo
>
> --
> Leonardo Lami
> email + jabber: lami at faunalia.it
> www.faunalia.it
> Cell: (+39)349-1310164  Tel+Fax: (+39) 0587-213742
> Piazza Garibaldi 5 - 56025 Pontedera (PI), Italy
>
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