NAflag: Set the NA flag

In terra: Spatial Data Analysis

Set the NA flag

Description

The main purpose of this method is to allow correct reading of a SpatRaster that is based on a file that has an incorrect or missing NA flag. The file is not changed, but the flagged value is set to NA when values are read from the file. In contrast, if the cell values are in memory the change is made immediately. NAflag does *not* return the "NoData Value" that is stored in the file (use describe to find that value.

To change cell values, you can use classify

Usage

## S4 method for signature 'SpatRaster'
NAflag(x)

## S4 replacement method for signature 'SpatRaster'
NAflag(x)<-value

Arguments

x	SpatRaster
value	numeric. The value to be interpreted as NA; set this before reading the values from the file. This can be a single value, or multiple values, one for each data source (file / subdataset)

Value

none or numeric

See Also

classify

Examples

 
s <- rast(system.file("ex/logo.tif", package="terra"))[[1]]   
NAflag(s) <- 255
plot(s)
NAflag(s)

terra documentation built on Aug. 22, 2026, 5:07 p.m.