QGIS » QGIS Application

The bug seems to be related ONLY on Windows system. A small dataset in attach.

Briefly: it seems that when using the Processing Raster calculator in Windows via pyqgis, it is not possible to use raster(s) entire path(s). Only raster names loaded in the TOC are available.

To reproduce the error:

• load the attached `calculated` raster in the TOC
• run this script (that uses gdal_proximity on the loaded raster and then the output of gdal_proximity is used in the raster calculator)

param_proximity = {
    'INPUT': QgsProject.instance().mapLayersByName('calculated')[0],
    'BAND': 1,
    'UNITS' : 0,
    'OUTPUT': os.path.join(output, 'distance.tif')
}

proximity = processing.run("gdal:proximity", param_proximity)

param_calculated = {
    'EXPRESSION':'{}@1 * {}'.format(proximity['OUTPUT'], formula),
    'LAYERS': proximity['OUTPUT'],
    'OUTPUT': os.path.join(output, 'calcolato.tif')
}

calculated = processing.run("qgis:rastercalculator", param_calculated)

iface.addRasterLayer(calculated['OUTPUT'], 'final')

This is working on Linux and on QGIS 3.4, 3.6 and master while is ALWAYS failing in Windows. To make it working on Windows some lines have to be added:

param_proximity = {
    'INPUT': QgsProject.instance().mapLayersByName('calculated')[0],
    'BAND': 1,
    'UNITS' : 0,
    'OUTPUT': os.path.join(output, 'distance.tif')
}

proximity = processing.run("gdal:proximity", param_proximity)
QgsProject.instance().addMapLayer(QgsRasterLayer(proximity['OUTPUT'], 'dummy'))
rl = QgsProject.instance().mapLayersByName('dummy')[0]

param_calculated = {
    'EXPRESSION':'{}@1 * {}'.format(rl.name(), formula),
    'LAYERS': rl.name(),
    'OUTPUT': os.path.join(output, 'calcolato.tif')
}

calculated = processing.run("qgis:rastercalculator", param_calculated)

iface.addRasterLayer(calculated['OUTPUT'], 'final')

Fianlly, but still extremely important, with the same data the result is completely different. On Windows there are some super strange values (1.79769e+308 adn -1.79769e+308): some serious trouble with NODATA values?