R: Class "STSDF"

STSDF-class {spacetime} | R Documentation

## 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))
      ## S4 method for signature 'STSDF'
    x[i, j, ..., drop = is(x, "STSDF")]
      ## S4 method for signature 'STSDF,STFDF'
    coerce(from, to, strict=TRUE)
      ## S4 method for signature '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 coercion to reduced classes takes place
`from` | object of class STFDF
`to` | target class
`strict` | ignored

### Objects from the Class

Objects of this class carry sparse space/time grid data

### Slots

`sp`:

  Object of class `"Spatial"`

`time`:

  Object holding time information; see ST-class for permitted types

`index`:

  matrix of dimension n x 2, where n matches the number of rows in slot data

`data`:

  Object of class `data.frame`, which holds the measured values

### Methods

[

  `signature(x = "STSDF")`: selects spatial entities, temporal entities, and attributes

plot

  `signature(x = "STS", y = "missing")`: plots space-time layout

plot

  `signature(x = "STSDF", y = "missing")`: plots space-time layout, indicating records partially NA

### Author(s)

Edzer Pebesma, edzer.pebesma@uni-muenster.de

### 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,])

[Package spacetime version 1.2-2 Index]