Calculate percentage table — lsm_percentage

Identifies percentage table.

Usage

lsm_percentage_table(
  input,
  output = NULL,
  multi_class = TRUE,
  binary_habitat_classes
)

Arguments

input: [character=""]
Habitat map, following a binary classification (e.g. values 1,0 or 1,NA for habitat,non-habitat) or multi-class map inside GRASS Data Base.
output: [character=""]
Map name output inside GRASS Data Base.
multi_class: [logical(1)=FALSE]
class_number_habitat: [numeric]

Examples

library(lsmetrics)
library(terra)

# read habitat data
r <- lsmetrics::lsm_toy_landscape(proj_type = "meters")

# plot
plot(r, legend = FALSE, axes = FALSE, main = "Binary habitat")
plot(as.polygons(r, dissolve = FALSE), lwd = .1, add = TRUE)
plot(as.polygons(r), add = TRUE)
text(r)


# find grass
path_grass <- system("grass --config path", inter = TRUE) # windows users need to find the grass gis path installation, e.g. "C:/Program Files/GRASS GIS 8.3"

# create grassdb
rgrass::initGRASS(gisBase = path_grass,
                  SG = r,
                  gisDbase = "grassdb",
                  location = "newLocation",
                  mapset = "PERMANENT",
                  override = TRUE)
#> gisdbase    grassdb 
#> location    newLocation 
#> mapset      PERMANENT 
#> rows        16 
#> columns     16 
#> north       7525600 
#> south       7524000 
#> west        234000 
#> east        235600 
#> nsres       100 
#> ewres       100 
#> projection:
#>  PROJCRS["WGS 84 / UTM zone 23S",
#>     BASEGEOGCRS["WGS 84",
#>         ENSEMBLE["World Geodetic System 1984 ensemble",
#>             MEMBER["World Geodetic System 1984 (Transit)"],
#>             MEMBER["World Geodetic System 1984 (G730)"],
#>             MEMBER["World Geodetic System 1984 (G873)"],
#>             MEMBER["World Geodetic System 1984 (G1150)"],
#>             MEMBER["World Geodetic System 1984 (G1674)"],
#>             MEMBER["World Geodetic System 1984 (G1762)"],
#>             MEMBER["World Geodetic System 1984 (G2139)"],
#>             ELLIPSOID["WGS 84",6378137,298.257223563,
#>                 LENGTHUNIT["metre",1]],
#>             ENSEMBLEACCURACY[2.0]],
#>         PRIMEM["Greenwich",0,
#>             ANGLEUNIT["degree",0.0174532925199433]],
#>         ID["EPSG",4326]],
#>     CONVERSION["UTM zone 23S",
#>         METHOD["Transverse Mercator",
#>             ID["EPSG",9807]],
#>         PARAMETER["Latitude of natural origin",0,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8801]],
#>         PARAMETER["Longitude of natural origin",-45,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8802]],
#>         PARAMETER["Scale factor at natural origin",0.9996,
#>             SCALEUNIT["unity",1],
#>             ID["EPSG",8805]],
#>         PARAMETER["False easting",500000,
#>             LENGTHUNIT["metre",1],
#>             ID["EPSG",8806]],
#>         PARAMETER["False northing",10000000,
#>             LENGTHUNIT["metre",1],
#>             ID["EPSG",8807]]],
#>     CS[Cartesian,2],
#>         AXIS["(E)",east,
#>             ORDER[1],
#>             LENGTHUNIT["metre",1]],
#>         AXIS["(N)",north,
#>             ORDER[2],
#>             LENGTHUNIT["metre",1]],
#>     USAGE[
#>         SCOPE["Navigation and medium accuracy spatial referencing."],
#>         AREA["Between 48°W and 42°W, southern hemisphere between 80°S and equator, onshore and offshore. Brazil."],
#>         BBOX[-80,-48,0,-42]],
#>     ID["EPSG",32723]] 

# import raster from r to grass
rgrass::write_RAST(x = r, flags = c("o", "overwrite"), vname = "r")
#> Over-riding projection check
#> Importing raster map <r>...
#>    0%   6%  12%  18%  25%  31%  37%  43%  50%  56%  62%  68%  75%  81%  87%  93% 100%
#> SpatRaster read into GRASS using r.in.gdal from memory

# percentage
lsmetrics::lsm_percentage_table(input = "r")
#> Calculationg habitat amount

# files
rgrass::execGRASS(cmd = "g.list", type = "raster")
#> r
#> r_habitat_amount_classes

# import from grass to r
da_pct <- readr::read_csv("r_percentage.csv")
#> Rows: 2 Columns: 4
#> ── Column specification ────────────────────────────────────────────────────────
#> Delimiter: ","
#> chr (1): perc
#> dbl (3): class, area_ha, ncell
#> 
#> ℹ Use `spec()` to retrieve the full column specification for this data.
#> ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.
da_pct
#> # A tibble: 2 × 4
#>   class area_ha ncell perc  
#>   <dbl>   <dbl> <dbl> <chr> 
#> 1     0 1460000   146 57.48%
#> 2     1 1100000   110 43.31%

# delete file
unlink("r_percentage.csv")

# delete grassdb
unlink("grassdb", recursive = TRUE)