Description Usage Arguments Details Value Author(s) Examples
Ignored values (aka 'nodata') are implemented via NA
values, and are optional for raster images in memory. However, to avoid ambiguity for data storage, it is desirable to specify ignored value. “ENVI .hdr Labelled Raster” supports ‘nodata’ by means of “data ignore value” field in the header file.
1 2 3 4 5 | ignorevalue(obj)
ursa_nodata(obj)
ignorevalue(obj) <- value
ursa_nodata(obj) <- value
|
obj |
|
value |
Integer of numeric of length one. Ignored (‘nodata’) value. |
ursa_nodata
is synonim to ignorevalue
for both Extract and Replace methods.
The ‘nodata’ value of raster image obj
is specified in the item obj$con$nodata
.
If values of raster image are in memory then replace function ignorevalue<-
also changes ‘nodata’ values to NA
values.
Extract function ignorevalue
returns value of $con$nodata
item of ursaRaster
object.
Replace function ignorevalue<-
returns ursaRaster
with modified $con$nodata
item.
Nikita Platonov platonov@sevin.ru
1 2 3 4 5 6 7 8 9 10 11 12 | session_grid(NULL)
a <- round(ursa_dummy(nband=1,min=0.500001,max=4.499999))
print(a)
print(as.table(a))
print(ignorevalue(a))
ignorevalue(a) <- NA
print(as.table(a))
print(ignorevalue(a))
ignorevalue(a) <- 4
print(as.table(a))
print(ignorevalue(a))
print(a)
|
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.