Override show() to save figures during CI

.github/workflows/examples.yml

@@ -59,31 +59,27 @@ jobs:
           EXAMPLE="examples/${{ matrix.example }}"
           EXAMPLE_DIR=$(dirname "${EXAMPLE}")
           EXAMPLE_FILE=$(basename "${EXAMPLE}")
-          FIGURE_DIR=$(realpath figs/)
-
-          echo "ARTIFACT_NAME=${EXAMPLE_FILE}" >> $GITHUB_ENV
-          echo "FIGURE_DIR=${FIGURE_DIR}" >> $GITHUB_ENV
-
-          mkdir -p "${FIGURE_DIR}"
-          python rhodium/test/plot_to_savefig.py "${EXAMPLE}" "${FIGURE_DIR}"
 
           pushd "${EXAMPLE_DIR}"
 
           if [ -f "Makefile" ]; then
             make
           fi
 
+          IMAGES_DIR=$(realpath images/)
+
           export RHODIUM_NO_PROMPT=true
+          export RHODIUM_FIGURE_OUTPUT="${IMAGES_DIR}"
           export LD_LIBRARY_PATH="$(pwd):${LD_LIBRARY_PATH}"
+
           python "${EXAMPLE_FILE}"
 
-          if [ -d "images/" ]; then
-            mv images/ "${FIGURE_DIR}"
-          fi
+          echo "IMAGES_DIR=${IMAGES_DIR}" >> $GITHUB_ENV
+          echo "ARTIFACT_NAME=${EXAMPLE_FILE}" >> $GITHUB_ENV
 
       - name: Upload figures
         uses: actions/upload-artifact@v4
         with:
           name: "${{ env.ARTIFACT_NAME }}"
-          path: "${{ env.FIGURE_DIR }}"
+          path: "${{ env.IMAGES_DIR }}"
           if-no-files-found: ignore

rhodium/plot.py

@@ -15,6 +15,7 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Rhodium.  If not, see <http://www.gnu.org/licenses/>.
+import os
 import mplcursors
 import matplotlib as mpl
 import matplotlib.pyplot as plt
@@ -29,6 +30,23 @@
 from .model import Response
 from .brush import BrushSet, apply_brush, color_brush, brush_color_map, color_indices
 
+# When set, override the plt.show() method to save.  Intended for CI
+# or headless mode.
+_figure_output_envvar = "RHODIUM_FIGURE_OUTPUT"
+
+if os.getenv(_figure_output_envvar):
+    def show_override(*args, **kwargs):
+        directory = os.getenv(_figure_output_envvar)
+
+        if not os.path.exists(directory):
+            os.makedirs(directory, exist_ok=True)
+
+        filename = os.path.join(directory, f"figure_{plt.gcf().number}.png")
+        plt.savefig(filename)
+        print(f"{_figure_output_envvar} set, saving figure to {filename}")
+
+    plt.show = show_override
+
 def _combine_keys(*args):
     result = []
     result_set = set()
@@ -423,6 +441,7 @@ def kdeplot(model, data, x, y,
             cmap=["Reds", "Blues", "Oranges", "Greens", "Greys"],
             **kwargs):
     df = data.as_dataframe()
+    plt.figure()
 
     if brush is None:
         sns.kdeplot(x=df[x],