ursa_new: Create raster image in memory

Description

ursa_new creates object of class ursaRaster in memory using session grid parameters or properties of input object (matrix or array). By option, band names and ignore values are specified.

Usage

ursa_new(...)

Arguments

…

Set of arguments, which are recognized via their names (using regular expressions) and classes:

value: Pattern is "(|^value)". Admissible classes are (matrix, array,numeric,logical. Values to fill image. Array or matrix defines raster grid. If value=FALSE (logical), then created raster image has no values. By default, value=NA, the created raster image is filled by blank values (NA).
nband: Positive integer. Number of bands. Default is 1L.
bandname: Character. Band names. Default is NULL. If specified, then nband is ignored, and the number of bands is equal to length of bandname character vector.
ignorevalue: Integer or numeric. Value in ENVI binary file, which is interpretted as NA in R.
datatype: Positive integer c(1L, 2L, 3L, 4L, 5L, 11L, 12L, 13L) or character. Data type (integer, floating-point) and byte length. See details for argument datatype of function create_envi. Required for writing raster to ENVI binart file. Optional for rasters in memory. Default is NA: data type is defined internally.
colortable: Object of class ursaColorTable. Color table for raster. Default is NULL: color table is absent
permute: Logical. Should dimensions of input matrix be changed. Default is FALSE.
flip: Logical. Vertical flip for input matrix. Default is FALSE: no flip.
crs: Character or object of class ursaGrid. The reference grid for raster's cells. Default is NULL: the grid is defined ether from matrix/array structure or from sessional parameters.
verb(ose)*: Logical. Value TRUE may provide some additional information on console. Default is FALSE.

Value

Object of class ursaRaster.

Details

ursa_new creates ursaRaster object in memory. To manipulate with raster chunks use the followed construction:

a <- create_envi(fname,...)
a[condition_1] <- value
print(a[condition_2]
...
close(a)

ursa_new is designed to create blank raster images. Use as.ursa for conversion R objects to ursaRaster.

Examples

Run this code

# NOT RUN {
session_grid(NULL)
a1 <- ursa_new(volcano)
print(a1)
display(a1)

a2 <- ursa_new(volcano,flip=TRUE)
print(a2)
display(a2)

a3 <- ursa_new(volcano,permute=TRUE)
print(a3)
display(a3)

dima <- c(200,300,4)
b1 <- as.ursa(array(runif(prod(dima)),dim=dima))
print(b1)
display_brick(b1,scale=1,palname="Greys",decor=FALSE)

session_grid(NULL)

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

c3 <- ursa_new(value=FALSE)
str(ursa_value(c3))

c4 <- ursa_new(bands=2,nodata=-99L)
print(c4)
print(ignorevalue(c4))

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

v <- ursa_value(c5[3:5])
str(v)
v <- c(v)
str(v)
c6 <- ursa_new(v,colortable=ct)
print(c6)
print(ursa_colortable(c6))
# }