Much thanks to all for these useful and informative responses.

I had come across the book in my searches but I had not stumbled onto its
homepage with the additional resources Roger has provided, which are
indispensable.  Perhaps to circumvent the potential conflict of interest you
could add a URL to your personal signature referring interested parties to a
website containing information on your related books and projects?  This to
me seems entirely reasonable as it does not solicit interest, it merely
provides access to that information.

I realize that have a different way of accessing the package vignettes (or
so I thought: http://cran.r-project.org/web/packages/sp/sp.pdf) so I haven't
necessarily been working with all the available information either.

I will keep Robert's handy conversion code nearby, which promises to make
creating sp objects quick and easy.

Thank you to Michael for his solution and encouragement.  I gathered that
the "ID" argument was critical to successfully passing the SpatialLines
command.  I considered doing a "for" loop, but when the following failed to
work with one mere record I decided there was no solution there to be found.

> flop<-Lines(Line(list(rbind(as.numeric(temp[1,7:8]),
as.numeric(temp[1,9:10])))), ID=row.names(temp))
> SpatialLines(flop)
Error in as.list.default(X) :
  no method for coercing this S4 class to a vector

Why is this?  Also to export my SLDF as a shapefile I would normally use the
following
> writeSpatialShape(ranslines, "C:/GIS/ranslines")

...but this is different from what Michael has proposed.
> writeOGR(sldf, ".", "ranlines", "ESRI Shapefile")

Is one method better than the other?

Tyler


On Tue, Feb 16, 2010 at 4:06 AM, Roger Bivand <Roger.Bivand@nhh.no> wrote:

> On Mon, 15 Feb 2010, Tyler Dean Rudolph wrote:
>
>  I have searched extensively for some good examples or documentation on how
>> to create a SpatialLinesDataFrame and for the life of me have found zilch.
>> This does not mean there is no such thing available, it just means that
>> wherever it is it is not readily accessible through the circuitous
>> pathways
>> of R help documentation or via a simple web search.
>>
>
> I have discussed with Achim Zeilis, who faces the same problem, the ethical
> appropriateness of mentioning our book on the Spatial Task View, and we've
> found until now that we shouldn't mention our own books. If opinion is that
> we should, and because they are in a number of university libraries, I can
> do that, and encourage Achim to do the same for Econometrics.
>
> If you visit the book website (http://www.asdar-book.org), you will find
> links to code showing how to do this (chapter 2). In addition, under
> "Additional materials", you find links to course materials, especially to a
> course given at Imperial College in 2007, in which a good deal of these
> questions are covered (see "Representing Spatial Data").
>
> Because the classes were designed as interface containers, most users do
> not need to know how to construct them from scratch, typically reading in
> data or coercing from other classes of objects. While the help pages could
> certainly be improved, we do provide a vignette that ships with the package,
> and where section 6 covers Line objects etc. See:
>
> http://cran.r-project.org/web/packages/sp/vignettes/sp.pdf
>
> or:
>
> vignette("sp", package="sp")
>
> in R.
>
> I'm sure that Mike's answer resolves your immediate problem - this is more
> of an answer to your general question about where to look for information
> about sp classes and how to make and use them.
>
> Hope this helps,
>
> Roger
>
>  As someone who
>> struggles daily to achieve highly technical things with scarcely the savvy
>> required, I wish there were more (or any?) examples in the documentation
>> for
>> most of the spatial packages available.  (I also wish that managing and
>> manipulating Spatial objects was about 65% less complicated, but for the
>> moment let's start with this)...
>>
>> I have a data.frame (temp) containing endpoints of animal trajectories
>> with
>> which I would like to create a SpatialLinesDataFrame for export into a
>> GIS.
>>
>>  temp
>>>
>>      id                 day       x        y        X2       Y2
>> 1 2002007 2005-04-04 12:01:01 -300358 748992.6 -300450.8 748764.8
>> 2 2002007 2005-04-04 12:01:01 -300358 748992.6 -301694.2 751728.4
>> 3 2002007 2005-04-04 12:01:01 -300358 748992.6 -299983.1 749528.8
>> 4 2002007 2005-04-04 12:01:01 -300358 748992.6 -300569.4 749640.7
>> 5 2002007 2005-04-04 12:01:01 -300358 748992.6 -300439.0 748308.8
>>
>> I seem reasonably able to create a Lines object (though I can't get the ID
>> argument to work for me where there are multiple records involved)....
>>
>>  ranlines<-apply(temp, 1,  function(x)
>>>
>> Lines(Line(list(rbind(as.numeric(x[7:8]), as.numeric(x[9:10]))))))
>>
>>  str(ranlines[[1]])
>>>
>> Formal class 'Lines' [package "sp"] with 2 slots
>>  ..@ Lines:List of 1
>>  .. ..$ :Formal class 'Line' [package "sp"] with 1 slots
>>  .. .. .. ..@ coords: num [1:2, 1:2] -300358 -300451 748993 748765
>>  .. .. .. .. ..- attr(*, "dimnames")=List of 2
>>  .. .. .. .. .. ..$ : NULL
>>  .. .. .. .. .. ..$ : chr [1:2] "X1" "X2"
>>  ..@ ID   : chr NA
>>
>> Am I at least on the right track?   Unfortunately now I'm clueless as to
>> what to do next because apparently Lines cannot be coerced to
>> SpatialLines,
>> and while I am normally able to figure my way out of things there is just
>> nothing intuitive about this as far as I can tell.  I have tried to create
>> SLDFs numerous times in the past and I have always been discouraged from
>> continuing.  I can create a psp object in Spatstat but I am equally unable
>> to convert that into a SLDF shape.  Terribly sorry about the rant but it's
>> difficulties like these that prevent a lot of people more clueless than me
>> from ever getting anywhere with R and more specifically the spatial
>> stuff....
>>
>> Tyler
>>
>>        [[alternative HTML version deleted]]
>>
>> _______________________________________________
>> R-sig-Geo mailing list
>> R-sig-Geo@stat.math.ethz.ch
>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>
>>
> --
> 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@nhh.no
>
>

	[[alternative HTML version deleted]]

