R: write STFDF to table forms

unstack {spacetime} | R Documentation

## write STFDF to table forms

### Description

create table forms of STFDF objects

### Usage

    ## S3 method for class 'STFDF'
    unstack(x, form, which = 1, ...)
    ## S3 method for class 'STFDF'
    as.data.frame(x, row.names, ...)

### Arguments

`x` | object of class `STFDF`
`form` | formula; can be omitted
`which` | column name or number to have unstacked
`row.names` | row.names for the data.frame returned
`...` | arguments passed on to the functions unstack or as.data.frame

### Value

`unstack` returns the data in wide format, with each row representing a spatial entity and each column a time; see unstack for details and default behaviour.

`as.data.frame` returns the data.frame in long format, where the coordinates of the spatial locations (or line starting coordinates, or polygon center points) and time stamps are recycled accordingly.

### 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)
    as.data.frame(stfdf, row.names = IDs)
    unstack(stfdf)
    t(unstack(stfdf))
    unstack(stfdf, which = 2)

[Package spacetime version 1.2-2 Index]