Add code for map generation

qgis/export.bat

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+set PYTHON="C:\Program Files\QGIS 3.20.3\bin\python-qgis.bat"
+
+%PYTHON% export.py
+
+pause

qgis/export.py

@@ -0,0 +1,103 @@
+"""export.py
+
+Export layouts from QGIS project to pdf or jpg.
+
+Each exported map will contain a different combination of EP/type, e.g.
+0.05/'ZSA'
+
+D Howe
+d.howe@wrl.unsw.edu.au
+2022-05-17
+"""
+import re
+import os
+from qgis.core import (
+    QgsApplication,
+    QgsProject,
+    QgsLayoutExporter,
+    QgsLayoutItemLabel,
+)
+
+QGZ_PATH = 'roches.qgz'
+OUTPUT_DIR = 'maps'
+FORMAT = 'jpg'
+
+# Initialise QGIS
+qgs = QgsApplication([], False)
+
+# Load project
+project = QgsProject.instance()
+project.read(QGZ_PATH)
+
+
+def unique_attributes(layer):
+    """Get unique values for year, EP, and profile"""
+    layer.setSubsetString('')  # Remove filter
+
+    # Get all available values for encounter probability and profile type
+    eps = []
+    types = []
+    years = []
+    for f in layer.getFeatures():
+        eps.append(f.attribute('ep'))
+        types.append(f.attribute('type'))
+        years.append(f.attribute('year'))
+
+    # Keep unique values
+    eps = list(set(eps))
+    types = list(set(types))
+    years = list(set(years))
+
+    return eps, types, years
+
+
+# Get layers with hazard lines (assuming there is a year in the layer name)
+map_layers = project.mapLayers().items()
+layers = [v for k, v in map_layers if re.search(r'\d{4}', v.name())]
+
+# Get all EP values and profile types from first hazard line layer
+eps, types, years = unique_attributes(layers[0])
+
+# BUG: repeat first file because of QGIS's incorrect legend placement
+years = [years[0]] + years
+
+# Get layouts
+layouts = project.layoutManager().layouts()
+
+# Create outout directory
+os.makedirs(OUTPUT_DIR, exist_ok=True)
+
+for layout in layouts:
+    name = layout.name()
+
+    # Set up plot settings
+    if FORMAT == 'pdf':
+        settings = QgsLayoutExporter.PdfExportSettings()
+        # settings.dpi = -1  # Native resolution
+        exporter = QgsLayoutExporter(layout).exportToPdf
+    elif FORMAT == 'jpg':
+        settings = QgsLayoutExporter.ImageExportSettings()
+        exporter = QgsLayoutExporter(layout).exportToImage
+    else:
+        raise ValueError("'FORMAT' must be 'jpg' or 'pdf'")
+
+    for t in types:
+        for e in eps:
+            for layer in layers:
+                year = re.search(r'\d{4}', layer.name()).group()
+                substring = f"ep='{e}' and type='{t}' and year={year}"
+                layer.setSubsetString(substring)
+
+            # Update label
+            label = f'Type: {t}\nEP: {e}'
+            for item in layout.items():
+                if isinstance(item, QgsLayoutItemLabel):
+                    item.setText(label)
+
+            map_path = os.path.join(OUTPUT_DIR, f'{name}-{t}-EP={e}.{FORMAT}')
+            print(f'Exporting {os.path.basename(map_path)}...')
+
+            res = exporter(map_path, settings)
+            if res != 0:
+                msg = 'Export failed. Does output folder exist?'
+                raise ValueError(msg)