Description Usage Arguments Details Value Author(s) See Also Examples
session_grid
without arguments returns current grid properties. session_grid
with arguments specifies grid, which is used by functions of this package, e.g., for plotting, for opened and created raster images during current session.
session_pngviwer
is used to permit external software to open PNG files.
session_tempdir
spefies directory for temporal files in some cases.
session_use_experimental_functions
allows to use undocumented (experimental) functions.
Group of functions session_proj4
, session_crs
, session_cellsize
, session_bbox
extracts certain properties of sessional grid.
1 2 3 4 5 6 7 8 9 | session_grid(obj)
session_proj4()
session_crs()
session_cellsize()
session_bbox()
session_pngviewer(allow = NA)
session_tempdir(dst = character())
session_use_experimental_functions()
|
obj |
Either missing, or |
allow |
Logical. If |
dst |
Character. Directory name for temporal files. Empty character or non-character is interpreted as |
session_grid
deals with option “ursaSessionGrid”: options(ursaSessionGrid=...)
or getOption("ursaSessionGrid")
.
Usage session_grid()
without arguments return value of “ursaSessionGrid” option via calling getOption("ursaSessionGrid")
. If is.null(getOption("ursaSessionGrid"))
then session_grid()
returns default CRS.
Usage session_grid(NULL)
resets “ursaSessionGrid” option via calling options(ursaSessionGrid=NULL)
.
The sequential calling
1 2 |
returns default CRS. For checking that the option has been resetted successfully, use getOption("ursaSessionGrid")
after session_grid(NULL)
session_proj4
and session_crs
are synonyms.
Object of class ursaGrid
. It is a list. Default values are grid parameters of NSIDC polar stereo gridded data of Northern hemispere with nominal gridded resolution 25 km (http://nsidc.org/data/polar_stereo/ps_grids.html).
1 2 3 4 5 6 7 8 9 10 11 12 13 | List of 9
$ columns: int 304
$ rows : int 448
$ resx : num 25000
$ resy : num 25000
$ minx : num -3850000
$ maxx : num 3750000
$ miny : num -5350000
$ maxy : num 5850000
$ proj4 : chr "+proj=stere +lat_0=90 +lat_ts=70.0 +lon_0=-45.0 +k=1
+x_0=0.0 +y_0=0.0 +a=6378273.000 +b=6356889.449 +units=m +no_defs"
- attr(*, "class")= chr "ursaGrid"
NULL
|
session_proj4
and session_crs
return item proj4
.
session_cellsize
returns squared root from multiplication of cell dimension: sqrt(resx*resy)
.
sessiong_pngviewer
returns value of getOption("ursaAllowPngViewer")
.
sessiong_bbox
returns named numeric of lenght 4: minimal x-coodrinate (xmin
), minimal y-coordinate (ymin
), maximal x-coordinate (xmax
), maximal y-coordinate (ymax
).
session_use_experimental_functions
added some non-public functions to current namespaces and returns invisile list of function names.
Nikita Platonov platonov@sevin.ru
Class ursaGrid
. Use regrid
to partial grid changing.
1 2 3 4 5 6 7 8 9 10 11 12 | session_grid(NULL)
getOption("ursaSessionGrid") ## NULL
(g1 <- session_grid()) ## default
g1$resx <- g1$resy <- 12500
g1$columns <- as.integer(with(g1,(maxx-minx)/resx))
g1$rows <- as.integer(with(g1,(maxy-miny)/resy))
session_grid(g1)
session_grid(NULL)
a <- ursa_new(value=3)
session_grid(a)
print(session_pngviewer())
|
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