spacetime (version 1.1-5)

STSDF-class: Class "STSDF"

Description

A class for spatio-temporal data with partial space-time grids; for n spatial locations and m times, an index table is kept for which nodes observations are available

Usage

STS(sp, time, index, endTime = delta(time))
  STSDF(sp, time, data, index, endTime = delta(time))
  ## S3 method for class 'STSDF':
[(x, i, j, ..., drop = is(x, "STSDF"))
  ## S3 method for class 'STSDF,STFDF':
coerce(from, to, strict=TRUE)
  ## S3 method for class 'STSDF,STIDF':
coerce(from, to, strict=TRUE)

Arguments

sp

object of class Spatial

time

object holding time information; see ST-class

data

data frame with rows corresponding to the observations (spatial index moving faster than temporal)

index

two-column matrix: rows corresponding to the nodes for which observations are available, first column giving spatial index, second column giving temporal index

endTime

vector of class POSIXct with end points of time intervals for the observations

x

an object of class STFDF

i

selection of spatial entities

j

selection of temporal entities (see syntax in package xts)

...

selection of attribute(s)

drop

if TRUE and a single spatial entity is selected, an object of class xts is returned; if TRUE and a single temporal entity is selected, and object of the appropriate Spatial class is returned; if FALSE, no coerc

from

object of class STFDF

to

target class

strict

ignored

Objects from the Class

Objects of this class carry sparse space/time grid data

References

http://www.jstatsoft.org/v51/i07/

See Also

delta

Examples

sp = cbind(x = c(0,0,1), y = c(0,1,1))
row.names(sp) = paste("point", 1:nrow(sp), sep="")
library(sp)
sp = SpatialPoints(sp)
library(xts)
time = xts(1:4, as.POSIXct("2010-08-05")+3600*(10:13))
m = c(10,20,30) # means for each of the 3 point locations
mydata = rnorm(length(sp)*length(time),mean=rep(m, 4))
IDs = paste("ID",1:length(mydata))
mydata = data.frame(values = signif(mydata,3), ID=IDs)
stfdf = STFDF(sp, time, mydata)
stfdf
stsdf = as(stfdf, "STSDF")
stsdf[1:2,]
stsdf[,1:2]
stsdf[,,2]
stsdf[,,"values"]
stsdf[1,]
stsdf[,2]
# examples for [[, [[<-, $ and $<- 
stsdf[[1]]
stsdf[["values"]]
stsdf[["newVal"]] <- rnorm(12)
stsdf$ID
stsdf$ID = paste("OldIDs", 1:12, sep="")
stsdf$NewID = paste("NewIDs", 12:1, sep="")
stsdf
x = stsdf[stsdf,]
x = stsdf[stsdf[1:2,],]
all.equal(x, stsdf[1:2,])