ursa_000: Get and set properties of raster image.

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

Get and set properties of raster image.

Description

For package description see.

ursa is a wrapper to initialize object of class ursaRaster, to get and to set properties for this object.

Usage

ursa(obj, attr, ...)
ursa(obj, attr, ...) <- value

Arguments

obj	Any numeric structure (scalar, matrix, array) for initializing. Object of class ursaRaster for extracting and assigning properties.
attr	Character. Name of property.
...	Arguments, which are passed for properties specification.
value	Value for property assignment.

Details

Initializing function ursa with missing argument attr is a wrapper for function as.ursa.

Matched pattern	Replace method?	Description of property	Implementation
"grid"	Yes	Raster grid (extent, projection, cellsize)	ursa_grid
"(proj|crs)"	Yes	Coordinate reference system	ursa_proj
"val"	Yes	Raster value in the internal storage format	ursa_value
"(colort|ct)"	Yes	Color table	ursa_colortable
"(categ|class)"	Yes	Names of categories	names(ursa_colortable(obj))
"name"	Yes	Band names	names
"(nodata|ignorevalue|bg)"	Yes	Value, which is interpreted as NA.	ignorevalue
"^table$"	No	Frequency of unique values	as.table
"cell"	No	Squared cell size	with(ursa_grid(obj),sqrt(resx*resy))
"^dim$"	No	Dimension of raster image	dim
"(extent|bbox)"	No	Spatial extent of raster image	with(ursa_grid(obj),c(xmin=minx,ymin=miny,xmax=maxx,ymax=maxy))
"(nrow|rows|lines)"	No	Number of rows of raster image	ursa_grid(obj)$rows
"(ncol|columns|samples)"	No	Number of columns of raster image	ursa_grid(obj)$columns
"con"	No	structure of connection	obj$con
"(info|meta(data)*)"	No	Metadata, brief info	ursa_info
"^file(name)*"	No	Connection name (filename)	obj$con$fname

Argument ... is used to specify band index or band pattern in ursa(obj,"value",...)

Value

Inititalizing function ursa (missing attr) returns object of class ursaRaster.

Extract function ursa returns object of respective property.

Replace function ursa<- returns object

Author(s)

Nikita Platonov [e-mail]

See Also

as.ursa

Examples

a1 <- ursa(volcano)
print(a1)
 ## to avoid over-timing during tests -- begin
   display(a1)
 ## to avoid over-timing during tests -- end

a2 <- ursa(volcano,flip=TRUE)
print(a2)
 ## to avoid over-timing during tests -- begin
   display(a2)
 ## to avoid over-timing during tests -- end 

a3 <- ursa(volcano,permute=TRUE)
print(a3)
 ## to avoid over-timing during tests -- begin
   display(a3)
 ## to avoid over-timing during tests -- end

a4 <- ursa(volcano,flip=TRUE,permute=TRUE)
print(a4)
 ## to avoid over-timing during tests -- begin
   display(a4)
 ## to avoid over-timing during tests -- end

dima <- c(200,300,4)
b1 <- ursa(array(runif(prod(dima)),dim=dima))
print(b1)
display_brick(b1,scale=1,pal.rotate=0,pal.hue=0,decor=FALSE)
session_grid(NULL)

c1 <- ursa(seq(3))
print(c1)
c2 <- ursa(seq(3),bands=3)
print(c2)

c3 <- ursa(value=FALSE)
str(ursa(c3,"value"))

c4 <- ursa(bands=2,nodata=-99L)
print(c4)
print(ursa(c4,"nodata"))

c5 <- ursa(bandname=format(Sys.Date()+seq(7)-1,"%A"))
ursa(c5,"value") <- rev(seq(nband(c5)))
c5 <- colorize(c5)
ct <- ursa(c5,"colortable")
print(c5)

v <- ursa(c5[3:5],"value")
str(v)
v <- c(v)
str(v)
c6 <- ursa(v,colortable=ct)
print(c6)
print(ursa(c6,"colortable"))

ursa documentation built on April 3, 2025, 6 p.m.