Title: | Read Data to via GDAL Warper to an Assumed Grid |
---|---|
Description: | Convenience wrapper for the GDAL raster warper library. Set a default context grid, an extent, dimension, projection, and then read any GDAL raster source into that grid. There are controls to augment metadata-poor sources (to override missing or incorrect extent or projection metadata), to set a desired grid for subsequent use, and ability to control options available by the GDAL warp library itself. This can be used to easily read data from any kind of raster data source, local files, online servers, bare URLs, and database connections. Data is read in generic form but we provide example wrappers for commonly used formats for raster data. |
Authors: | Michael D. Sumner [aut, cre] |
Maintainer: | Michael D. Sumner <[email protected]> |
License: | MIT + file LICENSE |
Version: | 0.0.1.9014 |
Built: | 2024-12-27 03:57:59 UTC |
Source: | https://github.com/hypertidy/gdalio |
Data may be one band (the default, first band) or many.
gdalio_graphics(dsn, bands = 1:3, ...) gdalio_matrix(dsn, ...) gdalio_array(dsn, ...) gdalio_image(dsn, ..., extent = NULL, dimension = NULL, projection = NULL) gdalio_data(dsn, ..., bands = 1L) gdalio_graphics(dsn, bands = 1:3, ...) gdalio_matrix(dsn, ...) gdalio_array(dsn, ...)
gdalio_graphics(dsn, bands = 1:3, ...) gdalio_matrix(dsn, ...) gdalio_array(dsn, ...) gdalio_image(dsn, ..., extent = NULL, dimension = NULL, projection = NULL) gdalio_data(dsn, ..., bands = 1L) gdalio_graphics(dsn, bands = 1:3, ...) gdalio_matrix(dsn, ...) gdalio_array(dsn, ...)
dsn |
character string, raster source understood by GDAL |
bands |
default 1L, but can be more, duplicated in different order, or 'NULL' for all |
... |
arguments passed to 'vapour::vapour_warp_raster' |
gdalio_data()
returns a list of vectors, gdalio_matrix()
and gdalio_array()
and
gdalio_graphics()
return
a matrix, array, matrix of the necessary shape, as used by image()
and plot()
.
The matrix of hex values returned by gdalio_graphics()
cannot really be placed on a spatial
plot window without a lot of extra work, but it's good for fast visuals to 'plot()' the output.
We can write helpers to plot this thing better but WIP atm.
list of numeric vectors
## Not run: f <- system.file("extdata/sst.tif", package = "vapour", mustWork = TRUE) g <- list(extent = c(130, 160, -60, -30), dimension = c(180, 100), projection = "+proj=longlat") gdalio_set_default_grid(g) v <- gdalio_data(f, band_output_type = "int") image(seq(130, 160, length.out = 181), seq(-60, -30, length.out = 101), matrix(v[[1]], g$dimension[1])[,g$dimension[2]:1], asp = 1.5) ## End(Not run)
## Not run: f <- system.file("extdata/sst.tif", package = "vapour", mustWork = TRUE) g <- list(extent = c(130, 160, -60, -30), dimension = c(180, 100), projection = "+proj=longlat") gdalio_set_default_grid(g) v <- gdalio_data(f, band_output_type = "int") image(seq(130, 160, length.out = 181), seq(-60, -30, length.out = 101), matrix(v[[1]], g$dimension[1])[,g$dimension[2]:1], asp = 1.5) ## End(Not run)
gdalio_data_hex
and gdalio_data_rgb
are a little strange in that they return a
vector of character strings and a list of numeric values respectively.
gdalio_data_rgb(dsn, bands = 1:3, ...) gdalio_data_hex(dsn, bands = 1:3, ...)
gdalio_data_rgb(dsn, bands = 1:3, ...) gdalio_data_hex(dsn, bands = 1:3, ...)
dsn |
character string, raster source understood by GDAL |
bands |
bands to read, assumes 1:3 (can be 1:4 or any ordering) |
... |
arguments passed to 'vapour::vapour_warp_raster' |
'gdalio_data_rgb()' a list of integer vectors, 'gdalio_data_hex()' a character vector of "#" colours
You can 'source()' the file path displayed by this function to define package-specific formats for the gdalio data.
gdalio_format_source()
gdalio_format_source()
Running the code in the file path displayed by this function will load functions for terra, stars, raster, and spatstat.
## Not run: source(gdalio_format_source()) ## End(Not run)
## Not run: source(gdalio_format_source()) ## End(Not run)
Title
gdalio_get_default_grid()
gdalio_get_default_grid()
grid specification (list of extent, dimension, projection)
gdalio_get_default_grid() gdalio_set_default_grid(list(extent = c(-1000, 1000, -2000, 2000), dimension = c(100, 200), projection = "+proj=longlat")) gdalio_get_default_grid() gdalio_set_default_grid()
gdalio_get_default_grid() gdalio_set_default_grid(list(extent = c(-1000, 1000, -2000, 2000), dimension = c(100, 200), projection = "+proj=longlat")) gdalio_get_default_grid() gdalio_set_default_grid()
Generate a default local grid to use for subsequent data reads.
gdalio_local_grid( x = 147, y = -42, buffer = 2500000, family = "laea", dim = if (dev.cur() == 1) { c(512, 512) } else { dev.size("px") } )
gdalio_local_grid( x = 147, y = -42, buffer = 2500000, family = "laea", dim = if (dev.cur() == 1) { c(512, 512) } else { dev.size("px") } )
x |
longitude |
y |
latitude |
buffer |
width either side of x, y |
family |
projection family (as per PROJ strings) |
dim |
size of grid nx, ny |
All arguments have default values.
list appropriate for gdalio_set_default_grid()
gdalio_local_grid() gdalio_local_grid(family = "stere")
gdalio_local_grid() gdalio_local_grid(family = "stere")
Input may be a list with extent
$dimension
, $projection
, which is c(xmin, xmax, ymin, ymax)
,
c(ncol, nrow)
, and string (accepted by GDAL as a projection input). Alternatively, use
a raster, stars, or terra object. Only simple cases of stars will work (regular grids with positive x, negative y transforms).
gdalio_set_default_grid( x, ..., extent = NULL, dimension = NULL, projection = NULL )
gdalio_set_default_grid( x, ..., extent = NULL, dimension = NULL, projection = NULL )
x |
grid specification, a list with '$extent, $dimension, $projection' or a spatial grid object see Details |
the grid specification (originally: nothing, used to set a default grid available globally)
gdalio_set_default_grid(list(extent = c(-1000, 1000, -2000, 2000), dimension = c(100, 200), projection = "+proj=longlat")) gdalio_set_default_grid()
gdalio_set_default_grid(list(extent = c(-1000, 1000, -2000, 2000), dimension = c(100, 200), projection = "+proj=longlat")) gdalio_set_default_grid()
Provides a data frame of online-accessible data sources. This is very incomplete and has no guarantee of success. It's your responsibility to check usage terms.
gdalio_sources()
gdalio_sources()
There is a table of sources 'provider', 'name', 'source' - source is a DSN in GDAL terms, you can query and read from it with GDAL.
srcs <- gdalio_sources() ttsa <- subset(srcs, provider == "tasmap" & name == "TTSA")$source ve <- subset(srcs, provider == "gdaltms" & name == "wms_virtualearth_street")$source gdalio_set_default_grid(list(extent = c(-1, 1, -1, 1) * 800, dimension = rep(min(dev.size("px")), 2L), projection = "+proj=laea +lat_0=-42.8826 +lon_0=147.3257")) source(gdalio_format_source()) tas_street <- gdalio_terra(ttsa, bands = 1:3, resample = "cubic") ve_street <- gdalio_terra(ve, bands = 1:3, resample = "cubic") par(mfrow = c(1, 2)) terra::plotRGB(tas_street) terra::plotRGB(ve_street)
srcs <- gdalio_sources() ttsa <- subset(srcs, provider == "tasmap" & name == "TTSA")$source ve <- subset(srcs, provider == "gdaltms" & name == "wms_virtualearth_street")$source gdalio_set_default_grid(list(extent = c(-1, 1, -1, 1) * 800, dimension = rep(min(dev.size("px")), 2L), projection = "+proj=laea +lat_0=-42.8826 +lon_0=147.3257")) source(gdalio_format_source()) tas_street <- gdalio_terra(ttsa, bands = 1:3, resample = "cubic") ve_street <- gdalio_terra(ve, bands = 1:3, resample = "cubic") par(mfrow = c(1, 2)) terra::plotRGB(tas_street) terra::plotRGB(ve_street)
Return a path to a data raster file, for easy access to examples.
gdalio_eg_raster() gdalio_eg_image()
gdalio_eg_raster() gdalio_eg_image()
This raster has sea surface temperature values in Celsius, with no colour palette defined.
gdalio_eg_raster() gdalio_eg_image()
gdalio_eg_raster() gdalio_eg_image()
Simple metadata augmentation for raster sources.
vrt(x, extent = NULL, projection = NULL) ## Default S3 method: vrt(x, extent = NULL, projection = NULL)
vrt(x, extent = NULL, projection = NULL) ## Default S3 method: vrt(x, extent = NULL, projection = NULL)
x |
character string, file, url, GDAL dsn |
extent |
numeric 'c(xmin, xmax, ymin, ymax)' |
projection |
character wkt, proj, epsg code |
Simple function to add either or both of a raster source extent and projection string.
The attributes from 'extent' as 'source_extent' and/or 'projection' as 'source_projection' are passed directly down to GDAL, via
the gdalio_data()
function, which hands them on to vapour::vapour_warp_raster()
arguments 'source_extent' and 'source_wkt'
respectively.
lightly classed character vector, with "vrt_simple", "character"
vrt("myfile.nc") vrt("myfile.nc", extent = c(-180, 180, -90, 90)) str(vrt("myfile.nc", extent = c(-180, 180, -90, 90), projection = 4326))
vrt("myfile.nc") vrt("myfile.nc", extent = c(-180, 180, -90, 90)) str(vrt("myfile.nc", extent = c(-180, 180, -90, 90), projection = 4326))