Update logic to prevent deprecation warnings (3.12+)

.github/workflows/run-image-comparison.yml

@@ -57,3 +57,14 @@ jobs:
       - name: Notify about a completed run
         if: success()
         run: echo "Image comparison testing completed successfully on ${{ matrix.os }}."
+
+      - name: Upload generated images and diffs
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: image-comparison-results-${{ runner.os }}
+          path: |
+            main/generated-example-images-adv/
+            main/generated-example-images-cont/
+          if-no-files-found: warn
+          retention-days: 7

CHANGELOG.md

@@ -16,7 +16,12 @@ of being developed elsewhere.
 
 ### Version `3.5.X`, first released 2026-10-09
 
-#### Version `3.5.0`, release 2026-10-09
+#### Version `3.5.1`, released 2026-??-??
+
+* Update code to prevent deprecation-related warnings
+  (https://github.com/NCAS-CMS/cf-plot/issues/72)
+
+#### Version `3.5.0`, released 2026-10-09
 
 * Modularise and refactor the codebase, which has no user-facing implications
   except that functionality is available via sub-modules as well as at the top-level

cfplot/__init__.py

@@ -21,7 +21,7 @@
 from .vector import vect
 
 __author__ = "Andy Heaps, Sadie Bartholomew, Bryan Lawrence"
-__maintainer__ ="Sadie Bartholomew"
+__maintainer__ = "Sadie Bartholomew"
 __date__ = "2026-10-09"
 
 

cfplot/blockfill.py

@@ -63,19 +63,20 @@ def _bfill(
         colmap = get_colour_scale_map()
         cmap = matplotlib.colors.ListedColormap(colmap)
         fill_colors = list(colmap)
-        if plotvars.levels_extend in ["min", "both"]:
-            cmap.set_under(plotvars.cs[0])
-        if plotvars.levels_extend in ["max", "both"]:
-            cmap.set_over(plotvars.cs[-1])
 
-        under_index = None
-        over_index = None
+        extremes = {}
         if plotvars.levels_extend in ["min", "both"]:
+            extremes["under"] = plotvars.cs[0]
             under_index = len(fill_colors)
             fill_colors.append(plotvars.cs[0])
         if plotvars.levels_extend in ["max", "both"]:
+            extremes["over"] = plotvars.cs[-1]
             over_index = len(fill_colors)
             fill_colors.append(plotvars.cs[-1])
+
+        if extremes:
+            cmap = cmap.with_extremes(**extremes)
+
     else:
         cols = single_fill_color
         cmap = matplotlib.colors.ListedColormap(cols)
@@ -447,10 +448,10 @@ def _bfill_ugrid(
 
     levs = deepcopy(np.array(clevs))
 
-    if plotvars.levels_extend == "min" or plotvars.levels_extend == "both":
+    if plotvars.levels_extend in ("min", "both"):
         levs = np.concatenate([[-1e20], levs])
     ilevs_max = np.size(levs)
-    if plotvars.levels_extend == "max" or plotvars.levels_extend == "both":
+    if plotvars.levels_extend in ("max", "both"):
         levs = np.concatenate([levs, [1e20]])
     else:
         ilevs_max = ilevs_max - 1

cfplot/colorbar.py

@@ -204,15 +204,19 @@ def cbar(
         )
 
         boundaries = levs.astype(float)
+        extremes = {}
         if extend in ("both", "min"):
-            cmap.set_under(plotvars.cs[0])
+            extremes["under"] = plotvars.cs[0]
             boundaries = np.insert(boundaries, 0, boundaries[0] - 1)
         if extend in ("both", "max"):
-            cmap.set_over(plotvars.cs[-1])
+            extremes["over"] = plotvars.cs[-1]
             boundaries = np.insert(
                 boundaries, len(boundaries), boundaries[-1] + 1
             )
 
+        if extremes:
+            cmap = cmap.with_extremes(**extremes)
+
         if not isinstance(levs, list):
             lbot = None
 

cfplot/colour/colour.py

@@ -668,15 +668,19 @@ def cbar(
         # Add colorbar extensions if definded by levs.  Using boundaries[0]-1
         # for the lower and boundaries[-1]+1 is just for the colorbar and
         # has no meaning for the plot.
+        extremes = {}
         if extend in ("both", "min"):
-            cmap.set_under(plotvars.cs[0])
+            extremes["under"] = plotvars.cs[0]
             boundaries = np.insert(boundaries, 0, boundaries[0] - 1)
         if extend in ("both", "max"):
-            cmap.set_over(plotvars.cs[-1])
+            extremes["over"] = plotvars.cs[-1]
             boundaries = np.insert(
                 boundaries, len(boundaries), boundaries[-1] + 1
             )
 
+        if extremes:
+            cmap = cmap.with_extremes(**extremes)
+
         if not isinstance(levs, list):
             lbot = None
 

cfplot/contour.py

@@ -469,10 +469,14 @@ def get_cmap(self) -> matplotlib.colors.ListedColormap:
         colmap = get_colour_scale_map()
         cmap = matplotlib.colors.ListedColormap(colmap)
 
+        extremes = {}
         if scale.levels_extend == "min" or scale.levels_extend == "both":
-            cmap.set_under(scale.cs[0])
+            extremes["under"] = plotvars.cs[0]
         if scale.levels_extend == "max" or scale.levels_extend == "both":
-            cmap.set_over(scale.cs[-1])
+            extremes["over"] = plotvars.cs[-1]
+
+        if extremes:
+            cmap = cmap.with_extremes(**extremes)
 
         return cmap
 

cfplot/trajectory.py

@@ -20,6 +20,29 @@
 from .state import plotvars
 
 
+def _trajectory_segments(x, y):
+    """Yield contiguous segments of finite, unmasked coordinates."""
+    x = np.ma.asarray(x, dtype=float)
+    y = np.ma.asarray(y, dtype=float)
+
+    x_data = x.filled(np.nan)
+    y_data = y.filled(np.nan)
+
+    valid = (
+        ~np.ma.getmaskarray(x)
+        & ~np.ma.getmaskarray(y)
+        & np.isfinite(x_data)
+        & np.isfinite(y_data)
+    )
+
+    edges = np.diff(np.r_[False, valid, False].astype(int))
+    starts = np.flatnonzero(edges == 1)
+    stops = np.flatnonzero(edges == -1)
+
+    for start, stop in zip(starts, stops):
+        yield start, stop, x_data[start:stop], y_data[start:stop]
+
+
 def traj(
     f=None,
     title=None,
@@ -305,22 +328,35 @@ def traj(
                 print("plotting markers")
 
             if legend_lines is False:
-                mymap.plot(
-                    xpts,
-                    ypts,
-                    color=linecolor,
-                    linewidth=plot_linewidth,
-                    linestyle=linestyle,
-                    marker=marker,
-                    markevery=markevery,
-                    markersize=plot_markersize,
-                    markerfacecolor=markerfacecolor,
-                    markeredgecolor=markeredgecolor,
-                    markeredgewidth=markeredgewidth,
-                    zorder=zorder,
-                    clip_on=True,
-                    transform=ccrs.PlateCarree(),
-                )
+                for start, stop, x_segment, y_segment in _trajectory_segments(
+                    xpts, ypts
+                ):
+                    segment_markevery = markevery
+                    if (
+                        isinstance(markevery, (int, np.integer))
+                        and markevery > 0
+                    ):
+                        segment_markevery = np.flatnonzero(
+                            np.arange(start, stop) % markevery == 0
+                        )
+                        segment_markevery -= start
+
+                    mymap.plot(
+                        x_segment,
+                        y_segment,
+                        color=linecolor,
+                        linewidth=plot_linewidth,
+                        linestyle=linestyle,
+                        marker=marker,
+                        markevery=segment_markevery,
+                        markersize=plot_markersize,
+                        markerfacecolor=markerfacecolor,
+                        markeredgecolor=markeredgecolor,
+                        markeredgewidth=markeredgewidth,
+                        zorder=zorder,
+                        clip_on=True,
+                        transform=ccrs.PlateCarree(),
+                    )
             else:
                 line_xpts = xpts.compressed()
                 line_ypts = ypts.compressed()

tests/integration/test_contour_plot_examples.py

@@ -104,7 +104,7 @@ def _assert_reference_match_strict(generated: Path, reference: Path) -> None:
     result = mpl_compare.compare_images(
         str(reference),
         str(generated),
-        tol=0.,
+        tol=0.0,
         in_decorator=True,
     )
     if result is not None: