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<p class="MsoNormal">I am trying to run a rastercalculator through a call to its python method and I get the error message core.QgsProcessingException: An error occurred while performing the calculation. Not a very intuitive message.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The variable _cutfill_nodata_file used in the code below is a path to a result from a previous geoprocessing call and the file does exist, but the call to rastercalculator seems to have an issue with that file. If I replace _cutfill_nodata_file
with self._elevation_layer.dataProvider().dataSourceUri()}@1 it works. Not what I want to do, but just wanted to test nothing odd about my expression. Do that basically adds the same layer to itself so I am doubling the cell values. I want to add the values
in the file _cutfill_nodata_file, but when I use that file, I get the error below. I tried using just the layer name and band which is what is used in the GUI raster calculator, but that does not work and I expect it to not as I think it only works if the
layers are in the layer panel which they are not, they are in a temp folder, so I am calling the method using the file names.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">elevation_30m_cutfill_file = os.path.join(</span><span style="font-size:10.5pt;font-family:Consolas;color:#569CD6">self</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">._temp_dir.name,
</span><span style="font-size:10.5pt;font-family:Consolas;color:#569CD6">f</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">"</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">{</span><span style="font-size:10.5pt;font-family:Consolas;color:#569CD6">self</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">._elevation_layer.name()}</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">_</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">{</span><span style="font-size:10.5pt;font-family:Consolas;color:#569CD6">self</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">.cutfill_layer.name()}</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">.tif"</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">)<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">elevation_30m_cutfill_name = os.path.splitext(os.path.basename(elevation_30m_cutfill_file))[</span><span style="font-size:10.5pt;font-family:Consolas;color:#B5CEA8">0</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">]<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">expression =
</span><span style="font-size:10.5pt;font-family:Consolas;color:#569CD6">f</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">'</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">\"{</span><span style="font-size:10.5pt;font-family:Consolas;color:#569CD6">self</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">._elevation_layer.dataProvider().dataSourceUri()}</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">@1</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">\"</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">
+ </span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">\"{_cutfill_nodata_file}</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">@1</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">\"</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">'</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4"><o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">processing.run(<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">
</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">"qgis:rastercalculator"</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">,
<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4"> {<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">
</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">'EXPRESSION'</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">:expression,<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">
</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">'LAYERS'</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">:[</span><span style="font-size:10.5pt;font-family:Consolas;color:#569CD6">self</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">._elevation_layer.dataProvider().dataSourceUri()],<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">
</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">'CELLSIZE'</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">:</span><span style="font-size:10.5pt;font-family:Consolas;color:#B5CEA8">0</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">,<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">
</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">'EXTENT'</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">:</span><span style="font-size:10.5pt;font-family:Consolas;color:#569CD6">None</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">,<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">
</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">'CRS'</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">:</span><span style="font-size:10.5pt;font-family:Consolas;color:#569CD6">None</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">,<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">
</span><span style="font-size:10.5pt;font-family:Consolas;color:#CE9178">'OUTPUT'</span><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4">:elevation_30m_cutfill_file<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4"> }<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:14.25pt;background:#1E1E1E"><span style="font-size:10.5pt;font-family:Consolas;color:#D4D4D4"> )<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> File "C:\Users\RDTECLAC\AppData\Roaming\QGIS\QGIS3\profiles\default\python\plugins\site_selection\tools\cutfill\cutfill_dialog.py", line 745, in _calculate_cutfill_elevation_layer<br>
processing.run(<br>
File "C:\PROGRA~1/QGIS31~1.16/apps/qgis-ltr/./python/plugins\processing\tools\general.py", line 108, in run<br>
return Processing.runAlgorithm(algOrName, parameters, onFinish, feedback, context)<br>
File "C:\PROGRA~1/QGIS31~1.16/apps/qgis-ltr/./python/plugins\processing\core\Processing.py", line 174, in runAlgorithm<br>
ret, results = execute(alg, parameters, context, feedback, catch_exceptions=False)<br>
File "C:\PROGRA~1/QGIS31~1.16/apps/qgis-ltr/./python/plugins\processing\gui\AlgorithmExecutor.py", line 71, in execute<br>
results, ok = alg.run(parameters, context, feedback, {}, False)<br>
_core.QgsProcessingException: An error occurred while performing the calculation<o:p></o:p></p>
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