points2network {shp2graph} | R Documentation |
A function to integrate an individual point data set into a network under different rules (see details below).
points2network(ntdata,pointsxy,approach=1,ELComputed=FALSE,longlat=F, Detailed=F, ea.prop=NULL)
ntdata |
A “SpatialLinesDataFrame” or “SpatialLines” object |
pointsxy |
A two-column matrix of point coordinates (X, Y) |
approach |
specified by an integer ranging from 1 to 4 to define the approach for integration: 1: Mapping each point to the nearest node in the network/graph 2: Mapping each point to the nearest point (add them as nodes if they are not) on the network 3: Add a new edge(virtual edge) between each point and the nearest node 4: Add a new edge(virtual edge) between each point and the nearest point |
ELComputed |
If TRUE, the length of each edge will be calculated and returned |
longlat |
If TRUE, distances on an ellipse with WGS84 parameters will be returned |
Detailed |
If TRUE, all the vertices within the polylines of a spatial network will be recognised as nodes; if FALSE, only two endpoints of each polyline are treated as nodes |
ea.prop |
A vector (of the length equalling to the number of edge attributes in in the network “ntdata”) with values of 1 or 0: 1: the corresponding column in the data frame will be kept for the new network; 0: the corresponding column in the data frame will not be kept. |
A list consisted of:
nodelist |
A “nodelist” object |
edgelist |
An “edgelist” object |
CoorespondIDs |
A vector of the cooresponding node ID for each point in “pointsxy” |
nodexlist |
A vector contains X-coordinates of all the nodes |
nodeylist |
A vector contains Y-coordinates of all the nodes |
Eadf |
A data frame of attributes of the returned edges, of which the structure is a data frame with [EdgeID,(attributes inherited from the input network data)] |
VElist |
A list of virtual edges if added, i.e. approaches 3 and 4 are used |
Edgelength |
If “ELComputed” is TRUE, lengths of all the edges will be returned as a numeric vector; otherwise it will be NULL. |
Binbin Lu lubinbin220@gmail.com
## Not run: data(ORN) pts<-spsample(ORN.nt, 100, type="random") ptsxy<-coordinates(pts)[,1:2] ptsxy<-cbind(ptsxy[,1]+0.008,ptsxy[,2]+0.008) #Mapping each point to the nearest node in the network/graph res<-points2network(ntdata=ORN.nt,pointsxy=ptsxy, approach=1) ptsinnt.view(ntdata=rn, nodelist=res[[1]], pointsxy=ptsxy, CoorespondIDs=res[[3]]) #Mapping each point to the nearest point (add them as nodes if they are not) on #the network res<-points2network(ntdata=ORN.nt,pointsxy=ptsxy, approach=2,ea.prop=rep(0,37)) ptsinnt.view(ntdata=ORN.nt, nodelist=res[[1]], pointsxy=ptsxy, CoorespondIDs=res[[3]]) #Add a new edge(Virtual edge) between each point and the nearest node res<-points2network(ntdata=ORN.nt,pointsxy=ptsxy, approach=3,ea.prop=rep(0,37)) VElist<-res[[7]] ptsinnt.view(ntdata=ORN.nt, nodelist=res[[1]], pointsxy=ptsxy, CoorespondIDs=res[[3]], VElist=VElist) #Add a new edge(Virtual edge) between each point and the nearest point res<-points2network(ntdata=ORN.nt,pointsxy=ptsxy, approach=4,ea.prop=rep(0,37)) VElist<-res[[7]] ptsinnt.view(ntdata=ORN.nt, nodelist=res[[1]], pointsxy=ptsxy, CoorespondIDs=res[[3]], VElist=VElist) ## End(Not run)