R: Class "STFDF"

STFDF-class {spacetime} | R Documentation

## Class "STFDF"

### Description

A class for spatio-temporal data with full space-time grid; for n spatial locations and m times, n x m observations are available

### Usage

      STF(sp, time, endTime = delta(time))
      STFDF(sp, time, data, endTime = delta(time))
      ## S4 method for signature 'STFDF'
    x[i, j, ..., drop = is(x, "STFDF")]
      ## S4 method for signature 'STFDF,xts'
    coerce(from, to, strict=TRUE)
      ## S4 method for signature 'STFDF,Spatial'
    coerce(from, to)

### Arguments

`sp` | object of class Spatial, having `n` elements
`time` | object holding time information, of length `m`; see ST for details
`endTime` | vector of class `POSIXct`, holding end points of time intervals; by default, time intervals equal the time step width, see delta
`data` | data frame with `n*m` rows corresponding to the observations (spatial index moving fastest)
`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

### Value

the `as.data.frame` coercion returns the full long table, with purely spatial attributes and purely time attributes replicated appropriately.

### Objects from the Class

Objects of this class represent full space/time data with a full grid (or lattice) layout

### Slots

`sp`:

  spatial object; see ST-class

`time`:

  temporal object; see ST-class

`data`:

  Object of class `data.frame`, which holds the measured values; space index cycling first, time order preserved

### Methods

[

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

coerce

  STFDF,xts

coerce

  STFDF,Spatial

(from) coerces to (wide form) SpatialXxDataFrame, where SpatialXx is the spatial class of from@sp

plot

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

plot

  `signature(x = "STFDF", y = "missing")`: plots space-time layout, indicating full missing valued records

### Author(s)

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

### References

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

### 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)
    time = 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
    stfdf[1:2,]
    stfdf[,1:2]
    stfdf[,,2]
    stfdf[,,"values"]
    stfdf[1,]
    stfdf[,2]
    as(stfdf[,,1], "xts")
    as(stfdf[,,2], "xts")
    # examples for [[, [[<-, $ and $<-
    stfdf[[1]]
    stfdf[["values"]]
    stfdf[["newVal"]] <- rnorm(12)
    stfdf$ID
    stfdf$ID = paste("OldIDs", 1:12, sep="")
    stfdf$NewID = paste("NewIDs", 12:1, sep="")
    stfdf
    x = stfdf[stfdf[1:2,],]
    all.equal(x, stfdf[1:2,])
    all.equal(stfdf, stfdf[stfdf,]) # converts character to factor...

[Package spacetime version 1.2-2 Index]