July 2018 – Landscape Archaeology

Lissage du modèle numérique de terrain BD ALTI

Le problème n’est pas nouveau, mais on ne trouve toujours pas de solutions simples pour le « maquillage » du modèle numérique de terrain (MNT) très couramment utilisé en France,…

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Benchmarking viewshed algorithm: Nuraghi of Sardinia

The new viewshed plugin for QGIS 3 features an improved algorithm which should result in perceptible improvements in terms of efficiency. So let’s give it a try! Nuraghe in Toralba-Sant'Antine…

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Looping through numpy arrays (e.g. moving/rolling window)

Numpy is the cornerstone of matrix based calculations in QGIS (and elsewhere). It does wonders with raster data (unless it hits the limit of available live memory…). A recurrent problem…

QGIS plugins

Visibility analysis for QGIS 3.0

Visibility analysis plugin is now available in QGIS 3.0! It has been completely refurbished: from now on it will be integrated into the “Processing toolbox”. This is a more appropriate…

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Tanaka method or how to make shaded contour lines

Contour lines have become a commonplace, unassuming companion of our cartographic outputs - GIS has made us forget their visual potential. Already in the 19th century cartographers experimented with shaded…