package_raster: Coercion to package 'raster' objects

In ursa: Non-Interactive Spatial Tools for Raster Processing and Visualization

Coercion to package 'raster' objects

Description

as.Raster converts singe-band ursaRaster object to raster, multi-band ursaRaster object to brick and list of ursaRaster objects to stack. S4 classes “raster”, “brick”, and “stack” are defined in package raster.

Usage

as.Raster(obj)

## S3 method for class 'ursaRaster'
as.Raster(obj)

## S3 method for class 'list'
as.Raster(obj)

## S3 method for class 'ursaStack'
as.Raster(obj)

## S3 method for class 'NULL'
as.Raster(obj)

Arguments

obj	Object of class ursaRaster or list of ursaRaster objects

Details

Package raster is required for conversions.

The uppercase ⁠as.⁠⁠R⁠⁠aster⁠ is important, because as.raster is used in internal functions for coercion to object of class raster.

Single-banded ursaRaster object (with or without colortable) is coerced to RasterLayer. Colortables are kept.
Multi-banded ursaRaster object is coerced to RasterBrick. Colortables are destroyed.
Multi-layered object (list of ursaRaster objects) is coerced to RasterStack. Colortables are destroyed.

Value

Either RasterLayer, RasterBrick, or RasterStack object.

If package raster is not installed then return value is NULL

Note

Package raster is marked as "Suggested".

Author(s)

Nikita Platonov [e-mail]

Examples

 ## test is skipped: raster's loading time is close to CRAN allowable test time
session_grid(NULL)
if (requireNamespace("raster")) {
   usedCRS <- ursa:::.crsForceProj4()
   ursa:::.crsForceProj4(TRUE) ## required for CRS comparison
   session_grid(regrid(mul=1/4))
   msk <- ursa_dummy(1,min=0,max=100)>40
   a1 <- ursa_dummy(1,min=200,max=500)[msk]
   a2 <- colorize(a1,ramp=FALSE,interval=FALSE,lazyload=FALSE)
   a3 <- as.integer(ursa_dummy(3,min=0,max=255.99))
   a4 <- ursa_stack(a3[msk])
   if (isLayer <- TRUE) {
      print(a1)
      r1 <- as.Raster(a1)
      message(as.character(class(r1)))
      print(r1)
      print(raster::spplot(r1))
      b1 <- as.ursa(r1)
      print(c(exported=a1,imported=b1,failed=b1-a1))
      print(c(theSameValue=identical(ursa_value(a1),ursa_value(b1))
             ,theSameGrid=identical(ursa_grid(a1),ursa_grid(b1))))
   }
   if (isLayerColortable <- TRUE) {
      r2 <- as.Raster(a2)
      message(as.character(class(r2)))
      print(r2)
      print(raster::spplot(r2))
      b2 <- as.ursa(r2)
      print(c(theSameValue=identical(ursa_value(a2),ursa_value(b2))
             ,theSameGrid=identical(ursa_grid(a2),ursa_grid(b2))))
   }
   if (isBrickOrRGB <- TRUE) {
      r3 <- as.Raster(a3)
      message(as.character(class(r3)))
      print(r3)
      print(raster::spplot(r3))
      raster::plotRGB(r3)
      b3 <- as.ursa(r3)
      print(c(theSameValue=identical(ursa_value(a3),ursa_value(b3))
             ,theSameGrid=identical(ursa_grid(a3),ursa_grid(b3))))
   }
   if (isStack <- TRUE) {
      r4 <- as.Raster(a4)
      message(as.character(class(r4)))
      print(r4)
      print(raster::spplot(r4))
      b4 <- as.ursa(r4)
      print(c(theSameValue=identical(ursa_value(a4),ursa_value(b4))
             ,theSameGrid=identical(ursa_grid(a4),ursa_grid(b4))))
   }
   ursa:::.crsForceProj4(usedCRS)
}

ursa documentation built on Sept. 30, 2024, 9:35 a.m.