[Raster-commits] r406 - pkg/raster/R

[noreply at r-forge.r-project.org]

Author: rhijmans
Date: 2009-04-15 06:00:14 +0200 (Wed, 15 Apr 2009)
New Revision: 406

Added:
   pkg/raster/R/rasterFromCells.R
Log:


Added: pkg/raster/R/rasterFromCells.R
===================================================================
--- pkg/raster/R/rasterFromCells.R	                        (rev 0)
+++ pkg/raster/R/rasterFromCells.R	2009-04-15 04:00:14 UTC (rev 406)
@@ -0,0 +1,24 @@
+# Author: Robert J. Hijmans, r.hijmans at gmail.com
+# International Rice Research Institute
+# Date :  April 2009
+# Version 0.8
+# Licence GPL v3
+
+
+rasterFromCells <- function(raster, cells) {
+	x <- unique(cells)
+	cols <- colFromCell(raster, x)
+	rows <- rowFromCell(raster, x)
+	res <- resolution(raster)
+	x1 <- xFromCol(raster, min(cols)) - 0.5 * res[1]
+	x2 <- xFromCol(raster, max(cols)) + 0.5 * res[1]
+	y1 <- yFromRow(raster, max(rows)) - 0.5 * res[2]
+	y2 <- yFromRow(raster, min(rows)) + 0.5 * res[2]
+	bb <- newBbox(x1, x2, y1, y2)
+	raster <- clearValues(raster)
+	cells2 <- cellsFromBbox(raster, bb)
+	r <- crop(raster, bb)
+	r[] <- cells2
+	return(r)
+}
+