components in raster logic

[mdsumner]

atm it's looking like

• vaster extent and cell and coord-access
• grout tiling and overviews (zoom levels)
• affinity a small special case, compare to py affine
• something meshy for conversion to segments and polygons and triangles
• something warpy for suggested warp output

[mdsumner]

a few examples here

https://gist.github.com/mdsumner/b844766f28910a3f87dc2c8a398a3a13

[mdsumner]

Let's build this bigger list, include stuff from affinity, grout, tabularaster, and others - probably a lot is misc and is there a more natural split. Also consistency around UI ...

misc

cell_from_extent <- function(dimension, extent, x_extent) {

extent_vrt <- function(x) {

vaster_listxyz <- function(extent, dimension, data = NULL) {
vaster_long <- function(extent, dimension, data = NULL, raster_order = TRUE) {
vcrop <- function(x, extent, dimension, ..., snap = "out") {

adjacencies

cell_kernel <- function(dimension, cell, size = 1) {
kernel_group_cell <- function(dimension, cell, size = 1) {

• the functions in affinity tl, bl, br, tr

grain, discretized crop/align

align_extent <- function(x, extent, dimension, snap = c("out", "near", "in")) {
e_dim <- function(x, extent, dimension) {
intersect_extent <- function(x_extent, extent, dimension) {
origin <- function(extent, dimension) {

cell functions get cells or operate by cells

• arranged by arguments of dimension, dimension+extent

'dimension'

cell_from_col <- function(dimension, col) {
cell_from_row <- function(dimension, row) {
cell_from_row_col <- function(dimension, row, col) {
cell_from_row_col_combine <- function(dimension, row, col) {
col_from_cell <-function(dimension, cell) {
row_from_cell <-function(dimension, cell) {

dimension+extent

cell_from_xy <- function(dimension, extent, xy) {
col_from_x <- function(extent, dimension, x) {
coords <- function(extent, dimension) {
extent_from_cell <- function(extent, dimension, cells) {

row_from_y <- function(extent, dimension, y) {
rowcol_from_cell <- function(extent, dimension, cell) {

x_from_cell <- function(extent, dimension, cell) {
x_from_col <- function(extent, dimension, col) {
xy_from_cell <- function(extent, dimension, cell) {

y_from_cell <- function(extent, dimension, cell) {
y_from_row <- function(extent, dimension, row) {

trivial, but helpful to have

n_cell <- function(dimension) {
n_col <- function(dimension) {
n_row <- function(dimension) {

x_centre <- function(extent, dimension) {
x_corner <- function(x) {

x_max <- function(extent) {
x_min <- function(extent) {
x_res <- function(extent, dimension) {
xlim <- function(extent) {
y_centre <- function(extent, dimension) {
y_corner <- function(x) {
y_max <- function(extent) {
y_min <- function(extent) {
y_res <- function(extent, dimension) {
ylim <- function(extent) {

• should extent have a NULL case, where it simply uses 0:ncol, 0:nrow
• [ ]

[mdsumner]

affinity package

There's a bunch of functions in affinity for rasters and little window vectors and transforms, these to be reworked into (extent, dimension) functions

• raster_to_gt is 'extent_dim_to_gt'
• 'gt_dim_to_extent' just is
• raster_to_world is geotransform(scale, offset)
• raster_to_rasterio is window(offset, srcdim, outdim)
• raster_to_rasterio and rasterio_to_sfio is 'window(offset, srcdim, outdim)` and the sf list of that
• geotransform_to_world and world_to_geotransform just reformat each other

raster_to_gt <- function(x) {
raster_to_world <- function(x) {
raster_to_rasterio <- function(x) {
raster_to_sfio <- function(x) {
gt_dim_to_extent <- function(x, dim) {
extent_dim_to_gt <- function(x, dim) {
raster_io0 <- function(src_offset, src_dim, out_dim = src_dim, resample = "NearestNeighbour") {
sfio_to_rasterio <- function(x) {
rasterio_to_sfio <- function(x) {
geo_transform0 <- function(px, ul, sh = c(0, 0)) {
world_to_geotransform <- function(x) {
geo_world0 <- function(px, ul, sh = c(0, 0)) {
geotransform_to_world <- function(x) {

[mdsumner]

need policies on

• treatment of multiple extent (dimension, extent, x_extent) etc
• when an extent is forced to align
• treatment of non-integer dimension (trunc, I think)
• functions of extent only, currently all are dimension,extent (because might be derived from dimension)
• row/col rowcol funs are currently row, col order - should change?
• [ ]

[mdsumner]

we need cell2cell for different cases aligned and not, exactextractr has it here in the small for raster/terra S4 when compared to its own 'grid'

https://github.com/isciences/exactextractr/blob/ca6bc75de7db0912c987702a0404380a8115d8c8/src/raster_utils.cpp#L52-L118

in vaster this is cell2cell (WIP) and has overlap with tiles stuff in grout:

vaster/R/tiles.R

Line 28 in 3e27df5

cell2cell <- function(dimension, extent, ## that's the parent