Chart Customization
Overview
Apollo provides a wide range of chart customization controls for adjusting how information is displayed, emphasizing important series, controlling axes, changing chart presentation, and preparing charts for analysis or reporting.
Chart customization is available alongside the standard chart-navigation controls in the Dashboard. Depending on the active viewer, you can customize:
- individual series and their visibility;
- line and series appearance;
- chart type;
- axis scaling;
- grid lines and labels;
- tooltips;
- chart layout;
- overlay appearance;
- chart animation;
- zoom and fullscreen presentation;
- exported chart appearance.
Not every option is available in every viewer. Some viewers have their own fixed chart types or specialized controls, while the common Chart Settings panel provides customization shared by the Dashboard chart engine.
Apollo uses Highcharts as its chart-rendering engine. The viewer determines the natural chart type and series displayed, while Chart Settings can override some visual properties.
What Chart Customization Is Used For
Chart customization is particularly useful when:
- you need to isolate one metric from a dense chart;
- several lines overlap and are difficult to distinguish;
- a series needs stronger visual emphasis;
- a chart needs a different visual representation;
- automatic Y-axis scaling makes two periods difficult to compare;
- you need to compare values using a consistent Y-axis range;
- axis labels or grid lines make a presentation too busy;
- you want tooltips positioned outside the chart;
- you want to prepare a chart for fullscreen viewing or export;
- you need to optimize a chart for a particular analysis workflow.
The customization controls do not change the underlying scenario data. They change how the loaded data is presented.
Series Visibility
Before changing the appearance of a series, it is useful to understand the difference between series visibility and series customization.
Show or Hide a Series
Charts that contain a legend allow you to click a legend entry to hide or show that series.
For example, a chart containing:
- Demand
- Generation
- Price
can be reduced to only the Demand and Generation series by hiding Price from the legend.
Hidden series remain part of the underlying chart data; they are simply not displayed.
Series visibility is tracked per chart type and remembered for the current session.
Reset Series Visibility
The Reset Series Visibility button in the Chart Toolbar restores all hidden series.
Its state provides a visual indication of whether the chart is currently displaying every series:
| State | Meaning |
|---|---|
| Amber / active | At least one series is hidden |
| Dimmed / inactive | No series are hidden |
When no series are hidden, clicking the button has no effect because the full series set is already visible.
Why This Matters
Hiding a series can be useful when:
- you are examining one particular metric;
- overlapping lines make a chart difficult to read;
- you are comparing only selected components;
- you are preparing a presentation view.
However, remember that a hidden series is not removed from the underlying data. It is only removed from the visible chart.
Individual Series Customization
The following controls are intended to help distinguish individual series visually.
The supplied reference guides confirm the existence and purpose of the common series and chart controls, but they do not document the exact mouse-button/context-menu implementation for every individual series customization. Where an option is exposed through Chart Settings or the documented legend controls, that behavior is described directly. Where the exact right-click workflow is not confirmed in the supplied source, the feature is not presented as a guaranteed interaction sequence.
Isolate Series
Isolating a series means focusing the chart on a particular metric by hiding the other visible series.
This is useful when a chart contains many series and you want to inspect one component without repeatedly hiding several series manually.
For example, on a Fuel Summary chart with many fuel types, isolating one fuel allows you to focus on its generation pattern without the other fuel bands competing for attention.
Line Width
Line width controls the visual thickness of a line series.
A thicker line can be useful when:
- emphasizing a primary metric;
- making a series easier to follow across a dense chart;
- improving readability in fullscreen mode;
- preparing charts for presentations or exported reports.
Use increased line width selectively. Making too many series thick at the same time can reduce the visual hierarchy of the chart.
Dash Style
Dash style changes the visual pattern of a line.
Different stroke patterns can help distinguish several overlapping series, particularly when color alone is insufficient.
Typical use cases include:
- differentiating two closely related metrics;
- improving grayscale or print readability;
- creating a stronger visual distinction between primary and secondary series.
Markers
Markers identify individual data points on a line series.
Turning markers On can make individual observations easier to locate, particularly when:
- the chart contains a relatively small number of data points;
- you are examining specific intervals;
- precise point identification is more important than a clean continuous line.
For dense time-series charts, markers may add visual clutter, so they are generally most useful when examining individual points rather than very large data sets.
Color
Series colours provide the primary visual distinction between multiple data series.
Changing a series colour can help:
- emphasize an important metric;
- improve contrast;
- distinguish related data sets;
- create a presentation-oriented visual hierarchy.
The exact colour behavior can vary by viewer. For example, the Fuel Summary viewer uses fixed fuel colours and explicitly does not allow those fuel colours to be changed.
This means that a customization available for a general series should not be assumed to override viewer-specific colour rules.
Series Type
Chart Settings includes a Type control that can override the natural chart type of the active viewer.
The confirmed selectable options are:
| Type | Description |
|---|---|
| Line | Displays values as connected lines |
| Area | Displays values as filled areas |
| Column | Displays values as vertical columns |
| Spline | Displays values using smoothed curves |
These are the confirmed user-selectable chart-type override options in the current source. Scatter, Step, and Horizontal Bar are not available as user-facing choices.
Natural Viewer Chart Types
Apollo's viewers can naturally use several different chart styles, including:
- Line charts
- Stacked area charts
- Boxplots
- Flow Duration Curves
- Column or stacked-column configurations
For example:
- Fuel Summary uses a stacked area chart.
- ProfilesView uses statistical boxplots.
- Flow Duration Curve View displays a duration curve.
- BidStack View uses a stacked representation of bid price buckets and may include line overlays.
The Chart Settings Type option is therefore an override of the active chart presentation rather than a replacement for the viewer system itself.
Changing the chart type can change how the data is visually interpreted. Use a chart type that remains appropriate for the underlying metric and the intended analytical purpose.
Axis Customization
Axis customization is one of the most important parts of Apollo chart configuration because the same series can appear very differently depending on the scale.
Automatic Y-Axis Scaling
Most viewers automatically scale the Y axis to the currently visible data range.
As you navigate to a quieter period, the Y axis may narrow. When you move to a high-demand or high-price period, the axis may expand again.
This is normal behavior and is the default scaling strategy for most viewers.
Start at Zero
The Start at Zero control forces the Y-axis minimum to zero instead of allowing the chart to choose an automatic minimum.
This is especially useful when reading absolute magnitudes.
For example, if a series varies between 800 MW and 1,000 MW, automatic scaling may display only the 800–1,000 MW range. Starting the axis at zero displays the full 0–1,000 MW range and makes the absolute scale clearer.
Viewer defaults are not identical:
| Viewer | Start at Zero default |
|---|---|
| BidStack View | On |
| Fuel Summary | On |
| Link View | Off |
| Other viewers | Generally Off |
The Link View defaults to Off because link-flow data can be bidirectional and forcing the axis to zero can obscure negative flows.
When Start at Zero is enabled, the chart resets any zoom that would otherwise hide the newly required zero-based range.
Freeze Y Axes
Freeze Y Axes captures the current Y-axis range and locks it while you navigate through time or switch scenarios.
This is particularly useful for comparing periods visually.
For example:
- Navigate to a representative period.
- Adjust the chart until the desired Y-axis range is visible.
- Enable Freeze Y Axes.
- Navigate to other periods.
- Compare the series without the chart automatically rescaling.
- Disable the control when you want automatic scaling again.
Without freezing, the Y axis can change significantly from one period to another, causing identical series to appear visually taller or shorter simply because the scale has changed.
The freeze state is tracked separately for the normal chart, Comparison View, and Profiles View.
Primary Axis Controls
The Chart Settings panel provides the following primary-axis controls:
| Setting | Function |
|---|---|
| Auto Scale | Automatically determines the visible axis range |
| Min | Manually specifies the minimum when Auto Scale is disabled |
| Max | Manually specifies the maximum when Auto Scale is disabled |
Manual Min/Max controls are shown when Auto Scale is disabled and the axis is not frozen.
Secondary Y Axis
Some viewers contain series with incompatible units.
A common example is a chart containing:
- Generation — MW
- Demand — MW
- Price — currency/MWh
In these cases, Apollo can use a secondary Y axis.
The secondary axis appears on the right side of the chart. In Chart Settings, the secondary axis provides:
- Lock to Primary
- Auto Scale
- Min
- Max
The Secondary Axis section only appears when a secondary axis is relevant to the active chart.
Level Axis
Storage View has a separate level axis because stored energy uses MWh while generation and demand use MW.
Chart Settings therefore provides a Level Axis section for Storage View with its own:
- Auto Scale
- Min
- Max
controls.
Grid Lines and Axis Labels
Chart Settings provides independent controls for grid lines.
| Setting | Default | Purpose |
|---|---|---|
| Y Major | On | Main horizontal grid lines |
| Y Minor | Off | Smaller horizontal divisions |
| X Major | Off | Main vertical grid lines |
| X Minor | Off | Smaller vertical divisions |
Major grid lines correspond to labelled axis positions, while minor grid lines provide additional subdivisions.
Axis Labels
The Axis Labels control shows or hides the axis label text.
This affects the axis titles and units, but does not remove the numerical scale values or grid lines.
It is useful when:
- preparing a presentation;
- maximizing available chart space;
- simplifying a screenshot;
- emphasizing the data rather than the surrounding chart annotations.
Tooltip Customization
Tooltips provide the values of the visible series at the selected X-axis position.
A tooltip normally contains:
- the X-axis label or timestamp;
- the series name;
- a colour indicator;
- the formatted value for each visible series.
The standard tooltip system can be configured in three ways.
| Location | Behavior |
|---|---|
| Right Panel | Values appear in the right-side panel instead of floating over the chart |
| Follow Cursor | A traditional tooltip follows the mouse |
| Floating | A draggable tooltip stays inside the chart |
Right Panel is the default.
The Floating tooltip remembers its position between sessions and can be reset to the top-right position by double-clicking its drag handle.
Enable or Disable Tooltips
Chart Settings also provides an Enable Tooltips master switch.
When disabled, tooltip values do not appear when hovering over the chart. The Location control is only available while tooltips are enabled.
Right Panel Tooltip
When Right Panel mode is used, the panel shows the hovered point's series values instead of placing a tooltip over the chart.
The Dashboard guide notes that up to 20 series can be displayed in the tooltip card. If the chart contains more, Apollo displays a +N more indicator.
Chart Layout
Apollo provides two chart-area layouts.
Layout 1 — Chart + Stats + Right Panel
This is the standard layout.
It provides:
- the main chart;
- the statistics bar below the chart;
- a right-side contextual panel.
The right panel can contain tooltip data, statistics details, fuel mix information, object information, or comparison information depending on the viewer and current state.
Layout 2 — Chart + Two Lower Panels
Layout 2 replaces the right-side panel with two lower panels.
The main chart occupies the upper section while the lower area is divided into:
- a wider left panel;
- a narrower right panel.
The Dock button is hidden because there is no right-side panel in this layout.
Chart Layout is configurable from Chart Settings.
The layout choice is remembered between application restarts and is stored per viewer.
Overlay Opacity
Chart Settings includes Overlay Opacity controls for in-chart overlays.
These controls affect the background opacity of:
- the chart title overlay;
- the floating tooltip box.
Separate controls are provided for light and dark themes.
The opacity range runs from:
- 0 — fully transparent;
- 1 — fully opaque.
This is useful when overlays obscure chart data or when a chart is being prepared for presentation.
Animations
The Animations setting controls whether chart transitions are animated.
Animations are enabled by default.
Turning animations off can improve performance when working with large data sets.
This can be useful when:
- navigating rapidly through large scenarios;
- switching viewers frequently;
- working with charts containing many series;
- prioritizing responsiveness over transition effects.
Zoom and Reset
Zoom controls let you focus on a smaller section of the currently displayed data.
Zoom In
Click and drag horizontally across the chart.
Apollo displays a selection region while dragging. Releasing the mouse zooms into that time range.
Reset Zoom
Click Reset Zoom to restore the chart to its full range.
Reset Zoom restores both the X and Y axes to the chart's full data range.
Reset Zoom is separate from resetting chart settings.
Reset All Settings
The Chart Settings panel provides Reset All Settings.
This restores the configurable chart settings to their factory defaults and clears the saved axis state.
Use:
- Reset Zoom when you only want to undo a zoom;
- Reset All Settings when you want to return the chart configuration to its defaults.
Statistics and Chart Customization
Chart customization also affects how statistics can be interpreted.
Statistics are calculated from the data currently loaded by the active viewer and update when the object, period, or underlying data changes.
Stat Cards
Stat cards are displayed below the chart in Layout 1 or in the lower panel in Layout 2.
They can contain:
- a statistic label;
- a primary value;
- optional supporting information such as sample counts or percentages.
The cards update as the visible time range changes.
Stat Detail
Clicking a stat card opens a detailed statistics card in the right panel.
Depending on the viewer, the details can include items such as:
- Min
- Q1
- Median
- Average
- Q3
- Max
- Count
- Sum
- Standard Deviation
The exact statistics depend on the active viewer and the statistic being examined.
Visible Time Range
The statistics normally respond to the selected period:
| Period | Statistics cover |
|---|---|
| D | Current day |
| W | Current week |
| M | Current month |
| A | Entire scenario range |
Therefore, changing D/W/M/A changes not only the chart but potentially the values shown by its statistic cards.
Comparison Mode
In comparison-enabled viewers, statistics can become comparison-aware.
Depending on the viewer, stat cards may display:
- values for multiple compared objects or scenarios;
- differences;
- percentage changes.
Clicking a stat can open a multi-column detail view containing per-object or per-scenario statistics.
Viewer-Specific Considerations
Chart customization should always be interpreted in the context of the active viewer.
The underlying series can change when:
- a different object is selected;
- a different viewer is selected;
- D/W/M/A changes;
- comparison mode is enabled;
- scenario data contains or lacks a particular series.
The legend always reflects the series available for the selected object, scenario, viewer, and current data set.
Example: BidStack View
BidStack View can contain multiple bid-price bucket series as well as Generation and, depending on the data, Demand and Price overlays.
Clicking a legend entry hides or shows individual bid-price buckets.
BidStack View also provides a Graph / Bid Table switch for Site and Unit objects, allowing the user to move between the chart and the underlying bid table.
Example: Net Load View
Net Load View uses stacked VRE Generation and Residual Load areas with Demand, Generation, and Price overlays.
Hiding Price removes its secondary Y axis. Hiding VRE Generation or Residual Load changes the visible composition of the stacked chart.
Example: Fuel Summary
Fuel Summary displays one series per fuel type present in the selected region.
Legend interactions allow individual fuel bands to be hidden or shown, but the viewer's fuel colours are fixed by the application's design palette.
Example: ProfilesView
ProfilesView is different from normal time-series viewers.
It uses a 24-hour boxplot representation and has controls for:
- Demand / Generation / Price;
- Day Type;
- Reset Zoom;
- Start at Zero;
- Freeze Y;
- Axis Labels;
- Tooltip;
- Export;
- Chart Settings;
- Reset Series Visibility;
- object comparison.
The normal D/W/M/A controls do not apply to ProfilesView because its X axis is always the 24 hours of the day.
Time Periods and Customization
Changing the D/W/M/A period changes the visible time window and may also change data granularity.
| Period | Typical granularity |
|---|---|
| D — Daily | Trading intervals, typically 30-minute or hourly |
| W — Weekly | Typically daily or interval data |
| M — Monthly | Daily aggregates |
| A — All | Monthly or longer aggregates |
Some viewers can aggregate data or omit series that are not meaningful at a particular resolution.
This means a chart customization should be interpreted together with the current time period.
For example:
- a marker may be useful in Daily view but visually overwhelming in All view;
- a frozen Y axis can make period-to-period comparison easier;
- a manually selected chart type may be more readable at one aggregation level than another.
Exporting a Customized Chart
The Chart Toolbar's Export control provides several output formats:
| Export option | Result |
|---|---|
| Print chart | Opens the browser print dialog |
| Download PNG | Chart image with transparent background |
| Download JPEG | Fixed 16:9 image, approximately 1920 × 1080 |
| Download PDF | A4-format PDF |
| Download SVG | Vector chart export |
| Download CSV | Underlying chart data |
| Download XLSX | Underlying chart data as an Excel workbook |
| Toggle fullscreen | Enters or exits fullscreen |
PNG, JPEG, PDF, and SVG exports represent the rendered chart, including its visible series, legend, and axis labels.
CSV and XLSX export the underlying numeric data for the series currently on the chart.
This distinction is important: an image export represents the visual presentation, while CSV/XLSX represents the data.
Fullscreen Presentation
The Fullscreen button expands the chart into browser fullscreen mode.
Fullscreen is especially useful when:
- inspecting a dense chart;
- presenting results;
- working with multiple series;
- reviewing tooltips and labels at a larger size.
Exit fullscreen by:
- clicking the fullscreen control again;
- pressing Escape;
- using the fullscreen option from the export menu.
Responsive Behavior
Apollo's chart toolbar adapts when the available width becomes smaller.
At reduced toolbar widths:
- the date text field can collapse into a calendar icon;
- toolbar controls remain available in compact form;
- chart actions remain accessible without requiring the full desktop width.
This allows chart navigation and customization controls to remain usable when the Dashboard window is resized.
Recommended Customization Workflows
For Detailed Analysis
- Select the object you want to analyze.
- Choose the viewer that answers the relevant question.
- Select the appropriate D/W/M/A period.
- Hide unnecessary series from the legend.
- Use Freeze Y Axes if you need to compare multiple periods.
- Use tooltip configuration to determine where detailed values should appear.
- Open Chart Settings for further axis, grid, visual, and layout controls.
- Use Reset Zoom when you are finished with a focused view.
For Presentation
- Hide unnecessary series.
- Set appropriate series colours and visual emphasis.
- Consider turning Axis Labels on or off depending on available space.
- Select the most suitable chart type.
- Adjust grid lines to reduce visual clutter.
- Choose Layout 1 or Layout 2 depending on whether the right-side contextual information is needed.
- Enter Fullscreen.
- Export to PNG, JPEG, PDF, or SVG.
For Comparing Periods
- Navigate to a representative period.
- Adjust the Y-axis to a useful range.
- Enable Freeze Y Axes.
- Move through D/W/M periods.
- Compare the series without allowing automatic Y-axis rescaling to change the visual proportions.
This workflow is particularly useful when looking for peaks, operational changes, or differences between time periods.
Important Notes and Limitations
- Not every customization applies to every viewer.
- Some viewers have fixed or specialized chart types.
- Some viewers have viewer-specific colour rules.
- Series can appear or disappear depending on the scenario's available data.
- Changing the selected object can completely replace the series set.
- Changing D/W/M/A can change the data granularity.
- Some viewers do not provide comparison mode.
- Some viewers do not have a statistics bar.
- Chart Settings may expose controls only when the corresponding chart feature exists.
- Secondary-axis settings appear only when a secondary axis is available.
- The Level Axis section is specific to Storage View.
- Reset Zoom and Reset All Settings are different operations.
- Hiding a series from the legend does not remove its underlying data.
- Exporting an image produces a visual representation of the chart, while CSV/XLSX exports the underlying chart data.
Do not assume that a setting available in one viewer is available in another. Apollo's viewers can have different series, chart types, axes, statistics, comparison capabilities, and viewer-specific controls.
Quick Reference
| Customization | Where to find it | Main purpose |
|---|---|---|
| Show / Hide Series | Chart legend | Remove visual clutter |
| Reset Series Visibility | Chart Toolbar | Restore all hidden series |
| Isolate Series | Series customization | Focus on one metric |
| Line Width | Series customization | Emphasize a line |
| Dash Style | Series customization | Distinguish overlapping lines |
| Markers | Series customization | Highlight individual points |
| Color | Series customization / viewer rules | Improve visual distinction |
| Type | Chart Settings → Visual | Change chart presentation |
| Start at Zero | Chart Toolbar / Chart Settings | Anchor Y axis at zero |
| Freeze Y Axes | Chart Toolbar / Chart Settings | Keep a consistent scale |
| Auto Scale | Chart Settings | Automatically fit the axis |
| Min / Max | Chart Settings | Manually control axis bounds |
| Secondary Axis | Chart Settings when available | Handle incompatible units |
| Grid Lines | Chart Settings | Control visual reference lines |
| Axis Labels | Toolbar / Chart Settings | Show or hide axis titles and units |
| Enable Tooltips | Chart Settings | Turn hover information on/off |
| Tooltip Location | Toolbar / Chart Settings | Choose tooltip placement |
| Chart Layout | Chart Settings | Control surrounding panels |
| Animations | Chart Settings | Control transitions and performance |
| Overlay Opacity | Chart Settings | Control overlay visibility |
| Reset Zoom | Chart Toolbar | Restore full chart range |
| Reset All Settings | Chart Settings | Restore chart configuration defaults |
| Fullscreen | Chart Toolbar | Maximize chart presentation |
| Export | Chart Toolbar | Save or print chart/data |
See Also
For the broader chart behavior behind these customization controls, see:
- Charts, Toolbars and Statistics — chart types, axes, time navigation, tooltip behavior, toolbar controls, layouts, and statistics.
- Viewer Reference — Part A — Summary, Historical Database, BidStack, Net Load, DGP, Price/Generation + Demand, Fuel Summary, Reserve Price, and Profiles.
- Viewer Reference — Part B — Comparison, AggregateStack, Economics, Storage, Contract Settlement, Flow Duration Curve, Regional Trace, Zonal Trace, and Sub-Group Trace.