Chart

View time series, instruments, and date sets on an interactive graph.

1. Overview

The Chart is one of the most-used tools in Hedgehog. It lets you visualize and compare time series data — stock prices, computed metrics, date sets, and more — on interactive XY charts with full control over renderers, axes, and annotations.

2. Getting Started

Open Chart from the Start Menu or the Navigation Bar.
Type a symbol (e.g., AAPL) in the expression bar at the bottom and press Enter.
The instrument's closing price series appears on the chart.
Click and drag on the chart to zoom into a date range. Right-click to reset the zoom.
Add more datasets by typing additional symbols or expressions.

3. Expression Bar

The expression bar (code editor) is located at the bottom of the chart window. Press Ctrl+E to focus it from anywhere in the window.

Type an instrument symbol (e.g., AAPL, MSFT) to add its default time series as a new dataset.
Use HHLang expressions for computed series, e.g., AAPL.close() / MSFT.close() for a relative price ratio.
Auto-completion helps find instruments, metrics, and functions as you type.

4. Datasets and Series

Each entry in the expression bar creates a dataset on the chart. A dataset may contain one or more series (e.g., an OHLC dataset contains open, high, low, and close series).

Click on a dataset's label or bubble to select it. This opens the Dataset ribbon tab.
Multiple datasets can be plotted simultaneously on the same subplot or on separate subplots.
Selected datasets can be renamed, recolored, or have their renderer changed.

5. Renderers

The renderer determines how a dataset is visualized. To change the renderer, click a dataset's label to select it, then choose a renderer from the Dataset ribbon tab.

Standard renderers

Renderer	Description
Line	Standard line chart connecting data points.
Area	Filled area under the line.
Bar	Vertical bars for single-series datasets.
Points	Scatter plot (points only, no connecting line).
Candlestick	OHLC data as candlestick bars. Requires an OHLC dataset.
OHLC	Open-High-Low-Close as thin bars. Requires an OHLC dataset.
Category Bar	Clustered bars for comparing multiple series side by side.

Multi-series renderers

Renderer	Description
Stacked Bar	Multiple series stacked vertically as bars.
Stacked Area	Multiple series stacked as filled areas.
Difference	Filled region between two series, colored by which is larger.
Band	A filled range (e.g., upper/lower bounds) between two series.

Event renderers

Renderer	Description
Dividend	Marks dividend payment events on the chart.
Stock Split	Marks stock split events.
Spinoff	Marks corporate spinoff events.
DateSet	Renders date set events as vertical markers or bands.

Hover over a renderer button to preview the change; move away to revert. Click to apply.

6. Subplots and Axes

A chart can have multiple subplots stacked vertically. All subplots share a common date (domain) axis but have independent range (value) axes.

Date axis

Configurable frequency: auto, daily, weekly, monthly, or yearly.
Custom date format and time zone.
Pan and zoom with click-drag.

Range axis

Auto-range or manual min/max bounds.
Linear or logarithmic scale.
Custom number format and margin control.
Multiple range axes on the same subplot alternate between left and right sides.

7. Annotations

Annotations can be drawn directly on the chart or attached to a specific dataset.

Annotation	Description
Line	Draw a line between two points.
Interval	Highlight a date range with a shaded band.
Text	Text label with optional HHLang expression parameters.
Shape	Draw rectangles, ovals, or other shapes.
Draw	Freeform drawing on the chart.
Trendlines	Linear regression trendline through data points.
% Change	Vertical marker showing percent change between two points on the Y axis.

8. Ribbon Tabs

Home

Compute — recalculate all datasets.
The expression bar at the bottom for adding datasets.

Export

See Exporting below.

Plot (contextual)

Appears when a subplot is selected. Controls subplot title, background color, domain axis range, and plot-level annotations.

Dataset (contextual)

Appears when a dataset is selected. Controls dataset name, renderer, annotations, metadata, and domain normalization.

Axis (contextual)

Appears when an axis is selected. Controls frequency, format, scale, range, and time zone.

9. Exporting

Action	Description
Copy to Clipboard	Copy all data as tab-delimited text (one date column, one column per series).
Copy Displayed Range to Clipboard	Same, but limited to the visible date range.
Export to Excel	Save all data to an `.xlsx` file.
Export Displayed Range to Excel	Same, limited to the visible range.
Export as Spreadsheet	Create a new Spreadsheet document from the chart data.
Export Displayed Range as Spreadsheet	Same, limited to the visible range.

10. Plot Settings

Each subplot exposes settings via the Plot ribbon tab:

Background color — customize the subplot background.
Gridlines — toggle and style domain/range gridlines.
Legend — show/hide and position the legend.
Zero baseline — draw a horizontal line at y=0.
Normalization — align all datasets to a common percentage baseline for comparison.

11. Tips

Use normalization to compare series with different scales on a percentage basis.
Logarithmic scale is useful for comparing percentage changes across different price levels.
Use Trendlines to quickly see linear trends in your data.
Add a Date Set as a dataset to overlay event markers (e.g., dates when a condition was met).

12. See Also

Dashboard — embed charts as widgets in a multi-page layout.
Spreadsheet — export chart data for further analysis.
Date Set — create date overlays for charts.
The Hedgehog Language — expression syntax for computed datasets.