ursaValue {ursa} | R Documentation |
Class ursaValue
is a part of class ursaRaster
. It contains values of image. In the case of numeric values, the exterior class is ursaNumeric
. In the case of categorical values, the exterior class is ursaCategory
.
## S3 method for class 'ursaCategory' print(x, ...) ## S3 method for class 'ursaNumeric' print(x, ...) ursa_value(obj, band) ursa_value(obj, band) <- value
x |
Object of the one of classes |
... |
Further arguments passed to generic functions |
obj |
Object of class |
band |
Optional. Vector of band numbers (positive integer) or band names (character). |
value |
Numeric or integer scalar, vector, or matrix. Coerced to dimenstion of |
Try to use high-level assignment using replacement [<-
operator for class ursaRaster
. However, if you don't get desired result, you can downgrade the level of your code.
Object of class ursaNumeric
is a numerical matrix. Object of class ursaCategory
is an integer matrix. Dimensions of this matrix:
dim(...)[1] |
Spatial domain; the length is muliplications of lines (rows) and samples (columns) |
dim(...)[2] |
Band or temporal domain; the length is number of bands |
It is allowed to use scalar value NA
in the case when values are not in memory. In this case the class is ursaValue
.
Nikita Platonov platonov@sevin.ru
Extract [
and replacement [<-
methods for class ursaRaster
session_grid(NULL) session_grid(regrid(mul=1/4)) a1 <- create_envi("exam1.envi",bandname=c("today","tomorrow")) str(ursa_value(a1)) close(a1) envi_remove("exam1") a2 <- ursa_dummy(nband=4,min=1,max=99) str(ursa_value(a2),digits=3) a3 <- as.integer(a2) str(ursa_value(a3)) str(ursa_value(a3,2)) print(ursa_value(a3)) print(a3) ursa_value(a3,"Band 2") <- 199 ursa_value(a3)[,3] <- 299 a3[4] <- 399 print(a3) ursa_value(a3[1:3]) <- ursa_value(a3[4]) print(a3) ursa_value(a3[1:3]) <- -c(1:3) print(a3)