The SAGA version of this algorithm is of limited use in QGIS, because the
volume calculated is embedded only in the SAGA terminal output. This prevents
it being saved to a file, or reused within a model as an input to a later
model step.
It's also very user-unfriendly, because users must know to manually scan
the algorithm log to find the SAGA output.
Given that the maths here is trivial, this commit ports the algorithm across
to be a native QGIS c++ algorithm. The algorithm duplicates the SAGA alg
1:1, but outputs the volume (and area) to either a HTML report, or a vector
table. Additionally, the outputs are exported as numeric outputs from the
algorithm, allowing them to be re-used within models.
(It's also considerably faster, because it avoids the forced conversion
to SAGA raster format)
Fixes#8607 (properly, even though that report is closed)
This allows optional creation of geodesic lines, which represent the
shortest distance between the points based on the ellipsoid.
When geodesic mode is used, it is possible to split the created lines
at the antimeridian (±180 degrees longitude), which can improve
rendering of the lines. Additionally, the distance between vertices
can be specified. A smaller distance results in a denser, more accurate
line.
Ports the similar algorithm from the shape tools plugin to c++, and utilises
built in QgsDistanceArea ellipsoidal calculations to split the lines.
This algorithm splits a line into multiple geodesic segments, whenever the
line crosses the antimeridian (±180 degrees longitude)
Splitting at the antimeridian helps the visual display of the lines in some
projections. The returned geometry will always be a multi-part geometry.
Whenever line segments in the input geometry cross the antimeridian,
they will be split into two segments, with the latitude of the breakpoint
being determined using a geodesic line connecting the points either side
of this segment. The current project ellipsoid setting will be used when
calculating this breakpoint.
If the input geometry contains M or Z values, these will be linearly
interpolated for the new vertices created at the antimeridian.
Supports in-place edit mode also.
These algorithms allow users to convert z or m values present in feature
geometries to attributes in the layer. By default the z/m value from the
first vertex in the feature is extracted, but optionally statistics
can be calculated on ALL the z/m values from the geometry (e.g. calculating
mean/min/max/sum/etc of z values).
Like the vector zonal stats algorithm, but this one works with
the zones defined in another raster.
Iterates over the input rasters in blocks to be nice and
memory efficient.
From the algorithm help:
"This algorithm calculates statistics for a raster layer's
values, categorized by zones defined in another raster layer.
If the reference layer parameter is set to "Input layer",
then zones are determined by sampling the zone raster layer
value at the centroid of each pixel from the source raster
layer.
If the reference layer parameter is set to "Zones layer",
then the input raster layer will be sampled at the centroid
of each pixel from the zones raster layer.
If either the source raster layer or the zone raster layer
value is NODATA for a pixel, that pixel's value will be
skipped and not including in the calculated statistics."
This is the processing side of the duplicate layer
names bug, while the core part was already fixed,
the processing logic was extended to handle inputs
from models and full-path references.
Fixes#20601
because they are available for most of the algs and wouldn't be used otherwise. Also when someone hits algA help button, he should be given the algA help and not the main gdal utility doc.
multipoint datasets
There's no single approach to use for multi-point inputs, so instead
of overloading this algorithm with extra options to control how these
are handled, we raise a helpful error and push the reponsibility back
to the user to get the data into the right format before running the
tool.
Fixes#20799
