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Grippa Tais committed Aug 25, 2021
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Expand Up @@ -9,9 +9,7 @@ <h2>DESCRIPTION</h2>

administrative units), into a raster grid with a finer spatial
resolution. Based on a vector layer with the response variable stored

in the attribute table and a raster map with categorical values (e.g. land

cover), the add-on will produce a raster with the weights to be used in
a dasymetric mapping operation that can be performed using <em><a
href="https://grass.osgeo.org/grass-stable/manuals/
Expand All @@ -26,13 +24,11 @@ <h2>DESCRIPTION</h2>

<p>A Random Forest (RF) regression model is trained at the level of the
vector spatial units. The user must specify a vector layer using the

<b>vector</b> parameter. The attribute table connected to this layer
must contain a column with a unique identifier (numeric),

specified via the <b>id</b> parameter. It must also contain a column
with the numeric value to be used as the response variable (e.g.

population count), specified via the <b>response_variable</b> parameter.

<p>The user must specify at least one categorical raster map,
Expand All @@ -42,10 +38,8 @@ <h2>DESCRIPTION</h2>
values (e.g. distance to the nearest road, school, hospital,
university...) with the parameter <b>distance_to</b>. From these raster
maps, the Random Forest's explanatory variables (i.e. covariates,
predictors) are calculated. For each of the categorical raster maps

(basemaps), the proportion of each class is calculated. For the

predictors) are calculated. For each of the categorical raster maps
(basemaps), the proportion of each class is calculated. For the
continuous raster map, the average values are calculated.

<p>Once trained, the Random Forest model predicts weights in a raster
Expand All @@ -54,14 +48,12 @@ <h2>DESCRIPTION</h2>
<b>output</b> parameter. The <b>tile_size</b> must be greater than
the spatial resolution of <b>basemap_a</b>. It it considered good
practice that the <b>tile_size</b> also be greater than the spatial
resolution of the other basemap and distance maps. The extent of the

resolution of the other basemap and distance maps. The extent of the
output weighted grid is created using the extent of the spatial units,
i.e. the <b>vector</b> parameter.

<p>By default, all classes from the raster basemap(s) are taken into
account. If the user wants only specific classes to be taken into account

account. If the user wants only specific classes to be taken into account
within the Random Forest model, it is possible to provide an optional
list of these classes with the <b>basemap_a_list</b> parameter (for
basemap_a) or the <b>basemap_b_list</b> parameter (for basemap_b, if
Expand All @@ -71,14 +63,12 @@ <h2>DESCRIPTION</h2>
and gives an indication about the internal accuracy of the model
(cross-validation on training set at the spatial units level). The log
of the Random Forest run (including the OOB error) is saved in a file
which path and name has to be specified via the <b>log_file</b>

which path and name has to be specified via the <b>log_file</b>
parameter. Using the <b>-f</b> flag, the log file will include extended
information about the cross-validation for each set of parameters
tested in the grid search.

<p>Feature importances in the model are plotted in a graph, which path

<p>Feature importances in the model are plotted in a graph, which path
and name has to be specified via the <b>plot</b> parameter. By default,
class values are used. Optionally, class labels can be used as plot
labels, using the flags <b>-a</b> and <b>-b</b>, for <b>basemap_a</b>
Expand All @@ -93,6 +83,9 @@ <h2>DESCRIPTION</h2>
<p>Parallel processing is supported. The number of cores to be used
should be specified via the <b>n_jobs</b> parameter.

<p>The addon is described in more details in a paper [3] with a case
study.

<h2>NOTES</h2>

<p>The module <a
Expand Down Expand Up @@ -466,6 +459,12 @@ <h2>REFERENCES</h2>
<i>Data, 4</i>(1), 13. <a
href="https://doi.org/10.3390/data4010013">https://doi.org/10.3390/
data4010013</a>
<p>[3] Flasse, C., T. Grippa, et S. Fennia. 2021. « A TOOL FOR MACHINE
LEARNING BASED DASYMETRIC MAPPING APPROACHES IN GRASS GIS ». The
International Archives of the Photogrammetry, Remote Sensing and
Spatial Information Sciences XLVI-4/W2-2021: 55‑62.
<a href="https://doi.org/10.5194/isprs-archives-XLVI-4-W2-2021-55-2021">
https://doi.org/10.5194/isprs-archives-XLVI-4-W2-2021-55-2021</a>

<h2>ACKNOWLEDGEMENT</h2>

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