[Qgis-user] basic contouring and kriging

[Firstname Lastname]

Thanks for the information above, it was very helpful and i now have a
better understanding of the interpolation process.
As a follow up question, i could not find the krigging function in the
processing toolbox, only TIN and IDW.  where do i look for the krigging
interpolation
Also, i understand the construction of delawney triangles and veronoi
diagrams now and how the veronoi cells are constructed.  What i am not
clear on is, once you have completed the interpolation and you have
your delawney triangle boundaries, how does this get translated to at
regular grid.
the triangular mesh is irregular, how does this get referred to a
rectangular grid?  if you have a brief description, that is adequate.


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On Mon, Dec 6, 2021 at 2:51 PM Nicolas Cadieux <njacadieux.gitlab at gmail.com>
wrote:

> Hi,
>
> Open the Processing toolbox panel, search for 'Krigging'.  You will see
> multiple SAGA modules. If you search for "interpolation", you will find IDW
> AND TIN under Q modules and other methods under the SAGA module. If you
> search for "grid" you will find multiple algorithms under GDAL/Raster
> analysis.  See https://gdal.org/tutorials/gdal_grid_tut.html#gdal-grid-tut
> and https://gdal.org/programs/gdal_grid.html  for other methods. This
> should cover it.
>
> The idea is generally to interpolate a raster surface from points or lines
> containing a z field or a z value (in 3D files).  After, you use
> Raster/Extract/Contour on this new raster layer.  You can also install the
> contour plugin.  That uses a point file only but I don't know the what
> algorithm it uses.
>
> You may find more algorithm using CrimeStat or GeoDa softwares.
>
> Hope this helps.
>
>
> Nicolas
>
>
>
> On 2021-12-06 1:59 p.m., Firstname Lastname wrote:
>
> hello group:
> i want to demonstrate some of the pitfalls of computer contouring methods
> with limited datasets.  i wanted to use a small dataset to demonstrate
> several contouring algorithms.  In particular, linear interpolation,
> inverse weighted, nearest neighbour and kriging.  Are any of these built
> into QGIS?  i do not see any options to control the contouring in the
> plugins for any options other than the default.
> thank you if you can provide any help.
>
> --
> Byron Veilleux, MSc. P.Geo
> Conjugate Geologic Services Limited
> Calgary, Alberta Canada
> byron at conjugategeo.com
> Cell:4037108414
>
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> --
> Nicolas Cadieuxhttps://gitlab.com/njacadieux
>
>
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