vec_read_window

Decodes only the tiles overlapping the requested window. Pixels outside
the raster extent come back as <code>NA</code>.

A minimal columnar query engine with lazy execution on datasets
larger than RAM. Provides 'dplyr'-like verbs (filter(), select(), mutate(),
group_by(), summarise(), joins, window functions) and common aggregations
(n(), sum(), mean(), min(), max(), sd(), first(), last()) backed by a
pure C11 pull-based execution engine and a custom on-disk format ('.vtr').
Reads and writes 'GeoTIFF' (including tiled and 'BigTIFF' layouts) and a
tiled raster format ('.vec') with overview pyramids and time cubes for
larger-than-RAM raster data.

Gilles Colling

vectra

Columnar Query Engine for Larger-than-RAM Data

vec_read_window function

<dl><dt>r</dt>
<dd>A <code>vectra_raster</code> from <code>vec_open_raster()</code>.</dd>
<dt>band</dt>
<dd>Band index (1-based). Default 1.</dd>
<dt>level</dt>
<dd>Overview level — 0 = full resolution, 1 = half, 2 =
quarter, etc. Must be &lt; <code>r$n_levels</code> (which is 1 unless
<code>vec_build_overviews()</code> has been run on the file).</dd>
<dt>cols</dt>
<dd>1-based column range <code>c(col_min, col_max)</code>. Inclusive.
Coordinates are in the chosen level's pixel grid (so at level 1 the
raster is half as wide). Default <code>c(1, level_width)</code>.</dd>
<dt>rows</dt>
<dd>1-based row range <code>c(row_min, row_max)</code>. Inclusive.
Default <code>c(1, level_height)</code>.</dd></dl>

Arguments

Read a window of pixels from a .vec raster — vec_read_window

<dl>

<dt>r</dt>
<dd>A <code>vectra_raster</code> from <code>vec_open_raster()</code>.</dd>


<dt>band</dt>
<dd>Band index (1-based). Default 1.</dd>


<dt>level</dt>
<dd>Overview level — 0 = full resolution, 1 = half, 2 =
quarter, etc. Must be &lt; <code>r$n_levels</code> (which is 1 unless
<code>vec_build_overviews()</code> has been run on the file).</dd>


<dt>cols</dt>
<dd>1-based column range <code>c(col_min, col_max)</code>. Inclusive.
Coordinates are in the chosen level's pixel grid (so at level 1 the
raster is half as wide). Default <code>c(1, level_width)</code>.</dd>


<dt>rows</dt>
<dd>1-based row range <code>c(row_min, row_max)</code>. Inclusive.
Default <code>c(1, level_height)</code>.</dd>

</dl>

vec_read_window: Read a window of pixels from a .vec raster

Description

Usage

Value

Arguments