return sftime object; addresses #104

DESCRIPTION

@@ -10,10 +10,8 @@ Authors@R: c(person(given = "Edzer",
      person("Benedikt", "Graeler", role = "aut"))
 Description: Variogram modelling; simple, ordinary and universal point or block (co)kriging; spatio-temporal kriging; sequential Gaussian or indicator (co)simulation; variogram and variogram map plotting utility functions; supports sf and stars.
 Depends: R (>= 2.10)
-Imports: utils, stats, graphics, methods, lattice, sp (>= 0.9-72), zoo,
-        spacetime (>= 1.2-7), FNN
-Suggests: fields, maps, mapdata, maptools, rgdal (>= 0.5.2), rgeos, sf
-        (>= 0.7-2), sftime, stars (>= 0.3-0), xts, raster, future, future.apply
+Imports: utils, stats, graphics, methods, lattice, sp (>= 0.9-72), zoo, sf (>= 0.7-2), sftime, spacetime (>= 1.2-8), stars, FNN
+Suggests: fields, maps, mapdata, maptools, rgdal (>= 0.5.2), rgeos, xts, raster, future, future.apply
 License: GPL (>= 2.0)
 URL: https://github.com/r-spatial/gstat/
 Encoding: UTF-8

NEWS.md

@@ -1,6 +1,6 @@
 # version 2.1-0
 
-* import `sftime`; modify `krigeST()` variogram functions to accept `sftime` objects as alternative to `STI` or `STIDF`
+* import `sftime`; modify `krigeST()` variogram functions to accept `sftime` objects for `data` (as alternative to `STI` or `STIDF`), and `stars` or `sftime` objects for `newdata`; #108 with great help from @henningte
 
 * fix Gaussian cosimulation, probably introduced in 2016, #106
 

R/krigeST.R

@@ -54,6 +54,7 @@ krigeST <- function(formula, data, newdata, modelList, beta, y, ...,
                     computeVar = FALSE, fullCovariance = FALSE,
                     bufferNmax=2, progress=TRUE) {
   stopifnot(inherits(modelList, "StVariogramModel") || is.function(modelList))
+  to_sftime = FALSE
   return_stars = if (inherits(data, c("stars"))) {
     if (!requireNamespace("sf", quietly = TRUE))
       stop("sf required: install that first") # nocov
@@ -73,8 +74,10 @@ krigeST <- function(formula, data, newdata, modelList, beta, y, ...,
 			newdata$._dummy = 0.
 		newdata = as(newdata, "STFDF")
 	}
-	if (inherits(newdata, "sftime"))
+	if (inherits(newdata, "sftime")) {
+  		to_sftime = TRUE
 		newdata = as(newdata, "STIDF")
+	}
     TRUE
   } else {
     if (!identical(data@sp@proj4string@projargs, newdata@sp@proj4string@projargs))
@@ -83,7 +86,6 @@ krigeST <- function(formula, data, newdata, modelList, beta, y, ...,
   }
   stopifnot(inherits(data, c("STF", "STS", "STI", "sftime")) && 
 			inherits(newdata, c("STF", "STS", "STI", "sftime"))) 
-  to_sftime = inherits(data, "sftime") # deal with later
   if (inherits(data, "sftime"))
     data = as(data, "STIDF")
   if (inherits(newdata, "sftime"))
@@ -113,7 +115,10 @@ krigeST <- function(formula, data, newdata, modelList, beta, y, ...,
 
     if (return_stars) {
 	  ret$._dummy = NULL
-      stars::st_as_stars(as(ret, "STFDF"))
+  	  if (to_sftime)
+		  sftime::st_as_sftime(ret)
+	  else 
+		  stars::st_as_stars(as(ret, "STFDF"))
 	} else
       ret
   } else {
@@ -128,8 +133,11 @@ krigeST <- function(formula, data, newdata, modelList, beta, y, ...,
     if (!fullCovariance) {
       ret = addAttrToGeom(geometry(newdata), df)
       if (return_stars) {
-        ret = stars::st_as_stars(as(ret, "STFDF"))
 	    ret$._dummy = NULL
+  	  	if (to_sftime)
+		  ret = sftime::st_as_sftime(ret)
+  		else 
+		  ret = stars::st_as_stars(as(ret, "STFDF"))
 	  }
       ret
     } else

demo/sftime.R

@@ -53,3 +53,9 @@ stplot(locKrig[,,"var1.pred"], col.regions=bpy.colors(), scales=list(draw=T))
 plot(locKrig_sft[1], col = sf.colors(), breaks = "equal")
 stplot(locKrig[,,"var1.var"], col.regions=bpy.colors(), scales=list(draw=T))
 plot(locKrig_sft[2], col = sf.colors(), breaks = "equal")
+
+st$foo = 0
+st_as_sf(st, long = TRUE) |> st_as_sftime() -> st.sftime
+locKrig_sft <- krigeST(z~1, sft, st.sftime, sumMetricModel, nmax=20, computeVar = T)
+plot(locKrig_sft["var1.pred"])
+

inst/ChangeLog

@@ -1,3 +1,46 @@
+2022-06-12  Edzer Pebesma <[email protected]>
+
+	* R/krigeST.R: remove ._dummy variable; #108
+
+2022-06-05  Edzer Pebesma <[email protected]>
+
+	* demo/00Index: update index
+
+2022-06-05  Edzer Pebesma <[email protected]>
+
+	* R/krigeST.R, demo/sftime.R: also handle stars with 0 arrays as
+	newdata
+
+2022-06-02  Edzer Pebesma <[email protected]>
+
+	* demo/sftime.R: add demo script
+
+2022-06-02  Edzer Pebesma <[email protected]>
+
+	* DESCRIPTION, R/krigeST.R, R/stVariogramModels.R, R/variogramST.R,
+	inst/ChangeLog, tests/stars.Rout.save: modifications to use sftime &
+	stars.
+
+2022-05-31  Edzer Pebesma <[email protected]>
+
+	* .Rbuildignore: tidy
+
+2022-05-31  Edzer Pebesma <[email protected]>
+
+	* NEWS.md: add news
+
+2022-05-31  Edzer Pebesma <[email protected]>
+
+	* src/mtrx.c: tidy
+
+2022-05-01  Edzer Pebesma <[email protected]>
+
+	* .github/workflows/tic.yml: GA, see #107
+
+2022-04-29  Edzer Pebesma <[email protected]>
+
+	* src/sim.c: fixes #106
+
 2022-04-12  Edzer Pebesma <[email protected]>
 
 	* R/stVariogramModels.R: replace | with || in if() calls

man/krigeST.Rd

@@ -64,6 +64,11 @@ krigeSTTg(formula, data, newdata, modelList, y, nmax=Inf, stAni=NULL,
  particular methods for ordinary spatio-temporal (ST) kriging. In particular,
  it does not support block kriging or kriging in a distance-based
  neighbourhood, and does not provide simulation.
+
+ If \code{data} is of class \code{sftime}, then \code{newdata} MUST be
+ of class \code{stars} or \code{sftime}, i.e. mixing form old-style
+ classes (package spacetime) and new-style classes (sf, stars, sftime)
+ is not supported.
 }
 
 \value{
@@ -73,8 +78,9 @@ krigeSTTg(formula, data, newdata, modelList, y, nmax=Inf, stAni=NULL,
 }
 
 \references{ 
-Spatio-Temporal Geostatistics using gstat.  Benedikt Graeler,
-Edzer Pebesma, Gerard Heuvelink.  The R Journal, accepted.
+Benedikt Graeler, Edzer Pebesma, Gerard Heuvelink.  Spatio-Temporal
+Geostatistics using gstat.  The R Journal 8(1), 204--218.
+\url{https://journal.r-project.org/archive/2016/RJ-2016-014/index.html}
 
 N.A.C. Cressie, 1993, Statistics for Spatial Data,
 Wiley.