intamap (version 1.5-7)

conformProjections: Getting conformed projections

Description

Getting a conformed projection for a set of Spatial* elements necessary for interpolation in the intamap-package.

Usage

conformProjections(object)

Value

A list of the parameters to be included in the object described in intamap-package

Arguments

object

an object of the type described in intamap-package

Author

Jon Olav Skoien

Details

conformProjections is a function that attempts to reproject all projected elements in object to one common projection. The function is usually called with an intamap object as argument from createIntamapObject if the parameter confProj = TRUE. Thus it is a function that is usually not necessary to call separately.

The need for this function is because several of the functions in a typical spatial interpolation work flow inside the intamap-package require that the elements have a common projection. In addition, there are some functions which are not able to deal with unprojected spatial objects, i.e. objects with coordinates given in lattitude and longitude. conformProjections will hence also attempt to reproject all elements that have coordinates in lattitude and longitude, even in the cases where they all have the same projections.

If only one of observations or predictionLocations has a projection (or is longlat), the other one is assumed to be equal. A warning is issued in this case.

The common projection depends on the object that is passed to conformProjections. First of all, if intCRS (see below) is present as an element of the object, all elements will be reprojected to this projection. If not, intCRS will be set equal to the first projection possible in the list below.

intCRS

Can be given as a component in object - and is the user-defined common projection used for interpolation

targetCRS

Can be given as a component in object - and is the user-defined target projections

predCRS

The projection of the predictionLocations in object

obsCRS

The projection of the observations

% This is the former version, where epsg:3035 was used as default. % \item{defaultCRS}{A default projection is used when all the components have % coordinates in lattitude and longitude, and no interpolation % or target projection is given. The chosen projection is % CRS("+init=epsg:3035") which is suitable for European data, % but not necessarily for data from other regions.}

References

Pebesma, E., Cornford, D., Dubois, G., Heuvelink, G.B.M., Hristopulos, D., Pilz, J., Stohlker, U., Morin, G., Skoien, J.O. INTAMAP: The design and implementation f an interoperable automated interpolation Web Service. Computers and Geosciences 37 (3), 2011.

Examples

data(meuse)
coordinates(meuse) = ~x+y
proj4string(meuse) <- CRS("+proj=stere +lat_0=52.15616055555555 
    +lon_0=5.38763888888889 +k=0.999908 +x_0=155000 +y_0=463000 +ellps=bessel +units=m")

predictionLocations = spsample(meuse, 50, "regular")

krigingObject = createIntamapObject(
	observations = meuse,
	predictionLocations = predictionLocations,
  formulaString = as.formula("log(zinc)~1"),
  intCRS = "+init=epsg:3035"
	)

krigingObject = conformProjections(krigingObject)
proj4string(meuse)
proj4string(krigingObject$observations)