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Create, modify, and delete cell values/layers/attributes of Spat* objects

Source: R/mutate-Spat.R
mutate.Spat.Rd

mutate() adds new layers/attributes and preserves existing ones on a Spat* object. transmute() adds new layers/attributes and drops existing ones. New variables overwrite existing variables of the same name. Variables can be removed by setting their value to NULL.

Usage

# S3 method for SpatRaster
mutate(.data, ...)

# S3 method for SpatVector
mutate(.data, ...)

# S3 method for SpatRaster
transmute(.data, ...)

# S3 method for SpatVector
transmute(.data, ...)

Arguments

.data

A SpatRaster created with terra::rast() or a SpatVector created with terra::vect().

...

<data-masking> Name-value pairs. The name gives the name of the layer/attribute in the output.

Value

A Spat* object of the same class than .data. See Methods.

terra equivalent

Some terra methods for modifying cell values: terra::ifel(), terra::classify(), terra::clamp(), terra::app(), terra::lapp(), terra::tapp()

Methods

Implementation of the generic dplyr::mutate(), dplyr::transmute() functions.

SpatRaster

Add new layers and preserves existing ones. The result is a SpatRaster with the same extent, resolution and crs than .data. Only the values (and possibly the number) of layers is modified.

transmute() would keep only the layers created with ....

SpatVector

The result is a SpatVector with the modified (and possibly renamed) attributes on the function call.

transmute() would keep only the attributes created with ....

See also

dplyr::mutate(), dplyr::transmute() methods.

terra provides several ways to modify Spat* objects:

Other single table verbs: arrange.SpatVector(), filter.Spat, rename.Spat, select.Spat, slice.Spat, summarise.SpatVector()

Other dplyr verbs that operate on columns: glimpse.Spat, pull.Spat, relocate.Spat, rename.Spat, select.Spat

Other dplyr methods: arrange.SpatVector(), bind_cols.SpatVector, bind_rows.SpatVector, count.SpatVector(), distinct.SpatVector(), filter-joins.SpatVector, filter.Spat, glimpse.Spat, group-by.SpatVector, mutate-joins.SpatVector, pull.Spat, relocate.Spat, rename.Spat, rowwise.SpatVector(), select.Spat, slice.Spat, summarise.SpatVector()

Examples


library(terra)

# SpatRaster method
f <- system.file("extdata/cyl_temp.tif", package = "tidyterra")
spatrast <- rast(f)

mod <- spatrast %>%
  mutate(exp_lyr1 = exp(tavg_04 / 10)) %>%
  select(tavg_04, exp_lyr1)

mod
#> class       : SpatRaster 
#> dimensions  : 87, 118, 2  (nrow, ncol, nlyr)
#> resolution  : 3881.255, 3881.255  (x, y)
#> extent      : -612335.4, -154347.3, 4283018, 4620687  (xmin, xmax, ymin, ymax)
#> coord. ref. : World_Robinson 
#> source(s)   : memory
#> names       :   tavg_04, exp_lyr1 
#> min values  :  1.885463, 1.207493 
#> max values  : 13.283829, 3.774934 
plot(mod)


# SpatVector method
f <- system.file("extdata/cyl.gpkg", package = "tidyterra")
v <- vect(f)

v %>%
  mutate(cpro2 = paste0(cpro, "-CyL")) %>%
  select(cpro, cpro2)
#>  class       : SpatVector 
#>  geometry    : polygons 
#>  dimensions  : 9, 2  (geometries, attributes)
#>  extent      : 2892687, 3341372, 2017622, 2361600  (xmin, xmax, ymin, ymax)
#>  source      : cyl.gpkg
#>  coord. ref. : ETRS89-extended / LAEA Europe (EPSG:3035) 
#>  names       :  cpro  cpro2
#>  type        : <chr>  <chr>
#>  values      :    05 05-CyL
#>                   09 09-CyL
#>                   24 24-CyL