raster: creating a layer of NA
Based on the example by Pierre:
logo <- raster(system.file("external/rlogo.grd", package="raster"))
# Use this rastre to create a new, void Raster object
r <- raster(logo)
show(r)
class : RasterLayer dimensions : 77, 101, 7777 (nrow, ncol, ncell) resolution : 1, 1 (x, y) extent : 0, 101, 0, 77 (xmin, xmax, ymin, ymax) projection : +proj=merc +ellps=WGS84 values : none # Set to NA r[] <- NA
show(r)
class : RasterLayer dimensions : 77, 101, 7777 (nrow, ncol, ncell) resolution : 1, 1 (x, y) extent : 0, 101, 0, 77 (xmin, xmax, ymin, ymax) projection : +proj=merc +ellps=WGS84 values : in memory min value : NA max value : NA So this should work for your raster: D10N2009[] <- NA Cheers, Lyndon
On Wed, May 25, 2011 at 2:32 AM, Roman Lu?trik <roman.lustrik at gmail.com> wrote:
I would use setValues on individual layer. Cheers, Roman On Wed, May 25, 2011 at 8:25 AM, Pierre Roudier <pierre.roudier at gmail.com>wrote:
Hi Agustin,
What about this:
# Create a Raster object
logo <- raster(system.file("external/rlogo.grd", package="raster"))
# Use this rastre to create a new, void Raster object
r <- raster(logo)
show(r)
Pierre
2011/5/25 Agustin Lobo <alobolistas at gmail.com>:
HI! I must create a layer with all missing values. I try:
show(D10N2009)
class ? ? ? : RasterBrick dimensions ?: 393, 606, 35 ?(nrow, ncol, nlayers) resolution ?: 0.008928571, 0.008928571 ?(x, y) extent ? ? ?: -2.004464, 3.40625, 40.49554, 44.00446 ?(xmin, xmax, ymin,
ymax)
projection ?: +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs
+towgs84=0,0,0
values ? ? ?:
/media/Iomega_HDD/FLUXPYR/VGTFLUXPYR1/D10/FLXP_NDD10_2009.vrt
min values ?: 0 0 0 0 0 0 0 0 0 0 ... max values ?: 255 255 255 255 255 255 255 255 255 255 ...
delme = D10N2009[[1]]*0 show(delme)
class ? ? ? : RasterLayer dimensions ?: 393, 606, 238158 ?(nrow, ncol, ncell) resolution ?: 0.008928571, 0.008928571 ?(x, y) extent ? ? ?: -2.004464, 3.40625, 40.49554, 44.00446 ?(xmin, xmax, ymin,
ymax)
projection ?: +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs
+towgs84=0,0,0
values ? ? ?: in memory min value ? : 0 max value ? : 0 But
delme = D10N2009[[1]]*NA
Error in D10N2009[[1]] * NA : non-numeric argument to binary operator I also try
NAvalue(delme) <- 0
but no trace of the NAs:
show(delme)
class ? ? ? : RasterLayer dimensions ?: 393, 606, 238158 ?(nrow, ncol, ncell) resolution ?: 0.008928571, 0.008928571 ?(x, y) extent ? ? ?: -2.004464, 3.40625, 40.49554, 44.00446 ?(xmin, xmax, ymin,
ymax)
projection ?: +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs
+towgs84=0,0,0
values ? ? ?: in memory min value ? : 0 max value ? : 0 By now I write with NAflag=0 and read back, but there must be a cleaner way of generating a layer with all NA values (it's a missing layer for a particular time) Thanks! Agus
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