diff --git a/flixopt/statistics_accessor.py b/flixopt/statistics_accessor.py
index 90ad875b7..cfa0f9f68 100644
--- a/flixopt/statistics_accessor.py
+++ b/flixopt/statistics_accessor.py
@@ -145,6 +145,128 @@ def _reshape_time_for_heatmap(
return result.transpose('timestep', 'timeframe', *other_dims)
+def _iter_all_traces(fig: go.Figure):
+ """Iterate over all traces in a figure, including animation frames.
+
+ Yields traces from fig.data first, then from each frame in fig.frames.
+ Useful for applying styling to all traces including those in animations.
+
+ Args:
+ fig: Plotly Figure.
+
+ Yields:
+ Each trace object from the figure.
+ """
+ yield from fig.data
+ for frame in getattr(fig, 'frames', []) or []:
+ yield from frame.data
+
+
+def _style_area_as_bar(fig: go.Figure) -> None:
+ """Style area chart traces to look like bar charts with proper pos/neg stacking.
+
+ Iterates over all traces in fig.data and fig.frames (for animations),
+ setting stepped line shape, removing line borders, making fills opaque,
+ and assigning stackgroups based on whether values are positive or negative.
+
+ Handles faceting + animation combinations by building color and classification
+ maps from trace names in the base figure.
+
+ Args:
+ fig: Plotly Figure with area chart traces.
+ """
+ import plotly.express as px
+
+ default_colors = px.colors.qualitative.Plotly
+
+ # Build color map and classify traces from base figure
+ # trace.name -> color, trace.name -> 'positive'|'negative'|'mixed'|'zero'
+ color_map: dict[str, str] = {}
+ class_map: dict[str, str] = {}
+
+ for i, trace in enumerate(fig.data):
+ # Get color
+ if hasattr(trace, 'line') and trace.line and trace.line.color:
+ color_map[trace.name] = trace.line.color
+ else:
+ color_map[trace.name] = default_colors[i % len(default_colors)]
+
+ # Classify based on y values
+ y_vals = trace.y
+ if y_vals is None or len(y_vals) == 0:
+ class_map[trace.name] = 'zero'
+ else:
+ y_arr = np.asarray(y_vals)
+ y_clean = y_arr[np.abs(y_arr) > 1e-9]
+ if len(y_clean) == 0:
+ class_map[trace.name] = 'zero'
+ else:
+ has_pos = np.any(y_clean > 0)
+ has_neg = np.any(y_clean < 0)
+ if has_pos and has_neg:
+ class_map[trace.name] = 'mixed'
+ elif has_neg:
+ class_map[trace.name] = 'negative'
+ else:
+ class_map[trace.name] = 'positive'
+
+ def style_trace(trace: go.Scatter) -> None:
+ """Apply bar-like styling to a single trace."""
+ # Look up color by trace name
+ color = color_map.get(trace.name, default_colors[0])
+
+ # Look up classification
+ cls = class_map.get(trace.name, 'positive')
+
+ # Set stackgroup based on classification (positive and negative stack separately)
+ if cls in ('positive', 'negative'):
+ trace.stackgroup = cls
+ trace.fillcolor = color
+ trace.line = dict(width=0, color=color, shape='hv')
+ elif cls == 'mixed':
+ # Mixed: show as dashed line, no stacking
+ trace.stackgroup = None
+ trace.fill = None
+ trace.line = dict(width=2, color=color, shape='hv', dash='dash')
+ else: # zero
+ trace.stackgroup = None
+ trace.fill = None
+ trace.line = dict(width=0, color=color, shape='hv')
+
+ # Style all traces (main + animation frames)
+ for trace in _iter_all_traces(fig):
+ style_trace(trace)
+
+
+def _apply_unified_hover(fig: go.Figure, unit: str = '', decimals: int = 1) -> None:
+ """Apply unified hover mode with clean formatting to any Plotly figure.
+
+ Sets up 'x unified' hovermode with spike lines and formats hover labels
+ as 'name: value unit'.
+
+ Works with any plot type (area, bar, line, scatter).
+
+ Args:
+ fig: Plotly Figure to style.
+ unit: Unit string to append (e.g., 'kW', 'MWh'). Empty for no unit.
+ decimals: Number of decimal places for values.
+ """
+ unit_suffix = f' {unit}' if unit else ''
+ hover_template = f'%{{fullData.name}}: %{{y:.{decimals}f}}{unit_suffix}'
+
+ # Apply to all traces (main + animation frames)
+ for trace in _iter_all_traces(fig):
+ trace.hovertemplate = hover_template
+
+ # Layout settings for unified hover
+ fig.update_layout(
+ hovermode='x unified',
+ xaxis_showspikes=True,
+ xaxis_spikecolor='gray',
+ xaxis_spikethickness=1,
+ )
+
+
# --- Helper functions ---
@@ -1529,13 +1651,14 @@ def balance(
unit_label = ds[first_var].attrs.get('unit', '')
_apply_slot_defaults(plotly_kwargs, 'balance')
- fig = ds.plotly.bar(
+ fig = ds.plotly.area(
title=f'{node} [{unit_label}]' if unit_label else node,
+ line_shape='hv',
**color_kwargs,
**plotly_kwargs,
)
- fig.update_layout(barmode='relative', bargap=0, bargroupgap=0)
- fig.update_traces(marker_line_width=0)
+ _style_area_as_bar(fig)
+ _apply_unified_hover(fig, unit=unit_label)
if show is None:
show = CONFIG.Plotting.default_show
@@ -1653,13 +1776,14 @@ def carrier_balance(
unit_label = ds[first_var].attrs.get('unit', '')
_apply_slot_defaults(plotly_kwargs, 'carrier_balance')
- fig = ds.plotly.bar(
+ fig = ds.plotly.area(
title=f'{carrier.capitalize()} Balance [{unit_label}]' if unit_label else f'{carrier.capitalize()} Balance',
+ line_shape='hv',
**color_kwargs,
**plotly_kwargs,
)
- fig.update_layout(barmode='relative', bargap=0, bargroupgap=0)
- fig.update_traces(marker_line_width=0)
+ _style_area_as_bar(fig)
+ _apply_unified_hover(fig, unit=unit_label)
if show is None:
show = CONFIG.Plotting.default_show
@@ -2249,15 +2373,22 @@ def storage(
else:
color_kwargs = _build_color_kwargs(colors, flow_labels)
- # Create stacked bar chart for flows
+ # Get unit label from flow data
+ unit_label = ''
+ if flow_ds.data_vars:
+ first_var = next(iter(flow_ds.data_vars))
+ unit_label = flow_ds[first_var].attrs.get('unit', '')
+
+ # Create stacked area chart for flows (styled as bar)
_apply_slot_defaults(plotly_kwargs, 'storage')
- fig = flow_ds.plotly.bar(
- title=f'{storage} Operation ({unit})',
+ fig = flow_ds.plotly.area(
+ title=f'{storage} Operation [{unit_label}]' if unit_label else f'{storage} Operation',
+ line_shape='hv',
**color_kwargs,
**plotly_kwargs,
)
- fig.update_layout(barmode='relative', bargap=0, bargroupgap=0)
- fig.update_traces(marker_line_width=0)
+ _style_area_as_bar(fig)
+ _apply_unified_hover(fig, unit=unit_label)
# Add charge state as line on secondary y-axis
# Only pass faceting kwargs that add_line_overlay accepts