Add UltraLayout: Advanced constraint-based positioning for non-orthogonal subplot arrangements

ultraplot/axes/base.py

@@ -1870,6 +1870,16 @@ def _get_size_inches(self):
         bbox = self.get_position()
         width = width * abs(bbox.width)
         height = height * abs(bbox.height)
+        dpi = getattr(self.figure, "dpi", None)
+        if dpi:
+            width = round(width * dpi) / dpi
+            height = round(height * dpi) / dpi
+        fig = self.figure
+        if fig is not None and getattr(fig, "_refnum", None) == self.number:
+            if getattr(fig, "_refwidth", None) is not None:
+                width = fig._refwidth
+            if getattr(fig, "_refheight", None) is not None:
+                height = fig._refheight
         return np.array([width, height])
 
     def _get_topmost_axes(self):
@@ -2791,6 +2801,79 @@ def _reposition_subplot(self):
             self.update_params()
             setter(self.figbox)  # equivalent to above
 
+        # In UltraLayout, place panels relative to their parent axes, not the grid.
+        if (
+            self._panel_parent
+            and self._panel_side
+            and self.figure.gridspec._use_ultra_layout
+        ):
+            gs = self.get_subplotspec().get_gridspec()
+            figwidth, figheight = self.figure.get_size_inches()
+            ss = self.get_subplotspec().get_topmost_subplotspec()
+            row1, row2, col1, col2 = ss._get_rows_columns(ncols=gs.ncols_total)
+            side = self._panel_side
+            parent_bbox = self._panel_parent.get_position()
+            panels = list(self._panel_parent._panel_dict.get(side, ()))
+            anchor_ax = self._panel_parent
+            if self in panels:
+                idx = panels.index(self)
+                if idx > 0:
+                    anchor_ax = panels[idx - 1]
+            elif panels:
+                anchor_ax = panels[-1]
+            anchor_bbox = anchor_ax.get_position()
+            anchor_ss = anchor_ax.get_subplotspec().get_topmost_subplotspec()
+            a_row1, a_row2, a_col1, a_col2 = anchor_ss._get_rows_columns(
+                ncols=gs.ncols_total
+            )
+
+            if side in ("right", "left"):
+                boundary = None
+                width = sum(gs._wratios_total[col1 : col2 + 1]) / figwidth
+                if a_col2 < col1:
+                    boundary = a_col2
+                elif col2 < a_col1:
+                    boundary = col2
+                # Fall back to an interface adjacent to this panel
+                boundary = min(
+                    max(
+                        _not_none(boundary, a_col2 if side == "right" else col2),
+                        0,
+                    ),
+                    len(gs.wspace_total) - 1,
+                )
+                pad = gs.wspace_total[boundary] / figwidth
+                if side == "right":
+                    x0 = anchor_bbox.x1 + pad
+                else:
+                    x0 = anchor_bbox.x0 - pad - width
+                bbox = mtransforms.Bbox.from_bounds(
+                    x0, parent_bbox.y0, width, parent_bbox.height
+                )
+            else:
+                boundary = None
+                height = sum(gs._hratios_total[row1 : row2 + 1]) / figheight
+                if a_row2 < row1:
+                    boundary = a_row2
+                elif row2 < a_row1:
+                    boundary = row2
+                boundary = min(
+                    max(
+                        _not_none(boundary, a_row2 if side == "top" else row2),
+                        0,
+                    ),
+                    len(gs.hspace_total) - 1,
+                )
+                pad = gs.hspace_total[boundary] / figheight
+                if side == "top":
+                    y0 = anchor_bbox.y1 + pad
+                else:
+                    y0 = anchor_bbox.y0 - pad - height
+                bbox = mtransforms.Bbox.from_bounds(
+                    parent_bbox.x0, y0, parent_bbox.width, height
+                )
+            setter(bbox)
+
     def _update_abc(self, **kwargs):
         """
         Update the a-b-c label.

ultraplot/axes/plot.py

@@ -3287,9 +3287,9 @@ def _parse_level_lim(
         for z in zs:
             if z is None:  # e.g. empty scatter color
                 continue
+            z = inputs._to_numpy_array(z)
             if z.ndim > 2:  # e.g. imshow data
                 continue
-            z = inputs._to_numpy_array(z)
             if inbounds and x is not None and y is not None:  # ignore if None coords
                 z = self._inbounds_vlim(x, y, z, to_centers=to_centers)
             imin, imax = inputs._safe_range(z, pmin, pmax)

ultraplot/figure.py

@@ -1841,6 +1841,8 @@ def _axes_dict(naxs, input, kw=False, default=None):
         # Create or update the gridspec and add subplots with subplotspecs
         # NOTE: The gridspec is added to the figure when we pass the subplotspec
         if gs is None:
+            if "layout_array" not in gridspec_kw:
+                gridspec_kw = {**gridspec_kw, "layout_array": array}
             gs = pgridspec.GridSpec(*array.shape, **gridspec_kw)
         else:
             gs.update(**gridspec_kw)