This seems impossible ( to get right, you can certainly get an answer) in general terms, do you really not know either an order of the points and/or their relative spacing in time?
On Fri, Jan 13, 2017, 03:18 marta azores <martazo...@gmail.com> wrote: > Dear forum members, > > I would like to know how join several points with the aim to track a ship. > > After reading the documentation of some packages, I decided to use the > function shortestPath, but I only got the line between the first and the > last location of my points list. I need the complete survey, including also > the middle points. I try a loop to build the survey of the boats using > their locations, but It didn't work to me. > > > Any idea? > > Thanks in advance, > > Marta > > #script# it's also attached in a R.file: question loop2.R > ########################################################## > # > #raster# it's attached > azoTS1<- raster("C:/Users/Documents/azoTS1.tif")#wgs84 > # > #10 points# it's attached > boat <- read.table("C:/Users/Documents/10pontos.csv", header=TRUE, > sep=",", na.strings="NA", dec=".", strip.white=TRUE)# > head(boat) > > #raster to transitionlayer > trCostS4<- transition(1/azoTS1, mean, directions=4) > > # points to spatialpointsdataframe > x=boat$Long1 > y=boat$Lat1 > coords = cbind(x, y) > plot(coords) > sp = SpatialPoints(coords, proj4string=CRS("+proj=longlat +ellps=WGS84 > +datum=WGS84"), bbox = NULL) > sp > spdf=SpatialPointsDataFrame(sp,boat) > spdf > nrow(spdf) > plot(sp,axes=TRUE) > plot(spdf,add=TRUE, axes=TRUE) > > #shortestpath > > ## 1) this script only join the first point of the list and the last one, > and the points in the middle are not used. > CostpathSPdf <- shortestPath(trCostS4, spdf[1,], spdf[10,], > output="SpatialLines") > plot(CostpathSPdf,add=TRUE,axes=TRUE,col=2)#R_plot1.png (it's attached) > > ## 2) this script didn't work to me > > #first way from website: > http://stackoverflow.com/questions/8127066/loop-or-sapply-function-for-multiple-least-cost-analysis-in-r?answertab=active#tab-top > for(i in 1:nrow(spdf)) { > # Computation > Costpath <- shortestPath(trCostS4, spdf[i,], spdf[10,], > output="SpatialLines") > plot(Costpath) > > } > > #Error in validObject(.Object) : > #invalid class “SpatialLines” object: bbox should never contain infinite > values > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Dr. Michael Sumner Software and Database Engineer Australian Antarctic Division 203 Channel Highway Kingston Tasmania 7050 Australia [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo