stInteraction {spacetime}

subtract marginal (spatial and temporal) means from observations

Description

subtract marginal (spatial and temporal) means from observations

Usage

 
stInteraction(x, ...)

Arguments

x

object of class STFDF

...

arguments passed to rowMeans, colMeans and mean, such as na.rm=TRUE

Value

object of class STFDF with each attribute replaced by its residual, computed by y_{ij}=x_{ij}-m_{.j}m{i.}/m with m the grand mean, m_{.j} the temporal mean, m_{i.} the spatial mean and m the grand mean.

Examples

if (require(gstat)) {
library(sp)
data(wind)
wind.loc$y = as.numeric(char2dms(as.character(wind.loc[["Latitude"]])))
wind.loc$x = as.numeric(char2dms(as.character(wind.loc[["Longitude"]])))
coordinates(wind.loc) = ~x+y
proj4string(wind.loc) = "+proj=longlat +datum=WGS84"
# match station order to names in wide table:
stations = 4:15
wind.loc = wind.loc[match(names(wind[stations]), wind.loc$Code),]
row.names(wind.loc) = wind.loc$Station
wind$time = ISOdate(wind$year+1900, wind$month, wind$day, 0)
space = list(values = names(wind)[stations])
wind.st = stConstruct(wind[stations], space, wind$time, SpatialObj = wind.loc)

wind.sti = stInteraction(wind.st)
# temporal means for any station should be zero:
c(mean(wind.sti[3,]),
# spatial mean for each time step should be zero:
mean(wind.sti[,5][[1]]))
}