Create a wind_series

Creates a wind_series, a time series of wind fields, from a raster, a list of rasters, or one or more raster files, such as the monthly files saved by download_wind_data(). Multiple inputs are combined into one series, in the order given, without reading the data into memory until needed.

Usage

wind_series(x, order = c("uuvv", "uvuv"))

Arguments

x

A multi-layer SpatRaster with layers containing u and v wind components; a list of them; or a character vector of paths to raster files. Each input must contain an equal number of u and v layers, arranged as given by order, and all inputs must share the same grid. Data must be on a longitude/latitude grid with square cells (equal x and y resolution in degrees), with u and v components in m/s, oriented to true east and north; see wind_rose().

order

Either "uuvv", the default, indicating that each input has all u components followed by all v components, or "uvuv", indicating alternating u and v components.

Value

A wind_series object, a SpatRaster with all the u layers of all inputs, followed by all the v layers, in time order.

See also

subset_series() and wind_times() for working with time steps.

Examples

series <- windscape_example("wind_series")
series
#> class       : SpatRaster
#> size        : 64, 96, 192  (nrow, ncol, nlyr)
#> resolution  : 0.3157895, 0.3174603  (x, y)
#> extent      : -120.1579, -89.84211, 29.84127, 50.15873  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 (EPSG:4326)
#> sources     : wind_usa.tif
#> names       : u 2000-01-01, u 200~00:00, u 200~00:00, u 200~00:00, u 2000-01-15, u 200~00:00, ...
#> min values  :         -0.4,        -0.4,        -0.6,        -0.6,         -0.4,        -0.5, ...
#> max values  :          0.7,           1,         0.9,           1,          0.7,         1.1, ...

# combine series stored in separate files, such as monthly files from download_wind_data()
files <- c(tempfile(fileext = ".tif"), tempfile(fileext = ".tif"))
terra::writeRaster(subset_series(series, steps = 1:48), files[1])
terra::writeRaster(subset_series(series, steps = 49:96), files[2])
wind_series(files)
#> class       : SpatRaster
#> size        : 64, 96, 192  (nrow, ncol, nlyr)
#> resolution  : 0.3157895, 0.3174603  (x, y)
#> extent      : -120.1579, -89.84211, 29.84127, 50.15873  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 (EPSG:4326)
#> sources     : file1f8e6ab55070.tif (96 layers)
#>               file1f8e2957e8e4.tif (96 layers)
#> names       : u 2000-01-01, u 200~00:00, u 200~00:00, u 200~00:00, u 2000-01-15, u 200~00:00, ...
#> min values  :         -4.7,        -4.7,        -6.4,        -6.9,         -4.7,        -5.7, ...
#> max values  :          7.8,        10.6,         9.4,        10.8,            7,        11.9, ...