meteo (version 2.0-3)

rfilltimegaps: Disaggregation in the time dimension through the use of splines for each pixel

Description

The function creates an object of STFDF-class class, spatio-temporal data with full space-time grid, from another STFDF-class and fills attribute data for missing values in time using splines.

Usage

rfilltimegaps(stfdf,
              tunits="day",
              attrname=1,
              ...)

Value

STFDF-class object with filled temporal gaps.

Arguments

stfdf

STFDF-class; object with time information of minimum length 2, and gap in time dimension.

tunits

character; increment of the sequence used to generete time infromation for temporal gap. See 'Details'.

attrname

integer or character; varible from STFDF-class to be splined in time.

...

arguments passed to splinefun, function spline.

Author

Milan Kilibarda

Details

tunits can be specified in several ways:

• A number, taken to be in seconds

• A object of class difftime

• A character string, containing one of "sec", "min", "hour", "day", "DSTday", "week", "month", "quarter" or "year". This can optionally be preceded by a (positive or negative) integer and a space, or followed by "s"

The difference between "day" and "DSTday" is that the former ignores changes to/from daylight savings time and the latter takes the same clock time each day. ("week" ignores DST (it is a period of 144 hours), but "7 DSTdays") can be used as an alternative. "month" and "year" allow for DST.)

References

Kilibarda, M., T. Hengl, G. B. M. Heuvelink, B. Graeler, E. Pebesma, M. Percec Tadic, and B. Bajat (2014), Spatio-temporal interpolation of daily temperatures for global land areas at 1 km resolution, J. Geophys. Res. Atmos., 119, 2294-2313, doi:10.1002/2013JD020803;

Kilibarda M., M. Percec Tadic, T. Hengl, J. Lukovic, B. Bajat - Spatial Statistics (2015), Global geographic and feature space coverage of temperature data in the context of spatio-temporal interpolation, doi:10.1016/j.spasta.2015.04.005.

See Also

rfillspgaps pred.strk

Examples

  data(nlmodis20110704)
  data(nlmodis20110712)
  data(NLpol)

  # fill spatial gaps
  library(raster)
  NLpol@proj4string <- nlmodis20110704@proj4string
  
  # \donttest{
  nlmodis20110704 <- rfillspgaps(nlmodis20110704,NLpol)
  nlmodis20110712 <- rfillspgaps(nlmodis20110712,NLpol)
  
  nlmodis20110704 <- as(nlmodis20110704,"SpatialPixelsDataFrame")
  names(nlmodis20110704)='m1'
  nlmodis20110712 <- as(nlmodis20110712,"SpatialPixelsDataFrame")
  names(nlmodis20110712)='m2'
  
  nlmodis20110704@data <- cbind(nlmodis20110704@data, nlmodis20110712@data)
  
  df<-reshape(nlmodis20110704@data , varying=list(1:2), v.names="modis",direction="long", 
            times=as.Date(c('2011-07-04','2011-07-12')), ids=1:dim(nlmodis20110704)[1])
  
  library(spacetime)
  stMODIS<- STFDF(as( nlmodis20110704, "SpatialPixels"), 
                  time= as.Date(c('2011-07-04','2011-07-12')), 
                  data.frame(modis=df[,'modis']))
  
  stplot(stMODIS, col.regions=bpy.colors())
  stMODIS <- rfilltimegaps(stMODIS)
  stplot(stMODIS, col.regions=bpy.colors())
  # }