Changelog

1.4.2

Statistics column editor: Added an info tooltip explaining the requirements for Cp, Cpk, Pp, and Ppk to appear (both LSL and USL must be configured, sufficient data points required).

Fix spec limits from feature series: LSL and USL control lines configured to pull values from a feature series field were not being resolved correctly; capability indices now reflect the actual series value.
Multi-series spec limit fallback: When a series has no LSL/USL configured, it now falls back to the limits defined for the first series, so a single pair of spec limits applies to all series by default.
Theme consistency: Replaced remaining hardcoded values with Grafana theme tokens — control line default colors now use the visualization palette (dark-green, dark-red, blue, etc.), hover range and tooltip offset use theme.spacing(), and annotation colors are resolved via theme.visualization.getColorByName().
Grafana dependency: Minimum required Grafana version bumped to 11.6.10.

Theme consistency: Replaced hardcoded pixel values and hex color constants with Grafana theme tokens (theme.spacing(), theme.colors.*, theme.visualization.getColorByName()) across editor and tooltip components, improving light/dark mode consistency.
Documentation: Updated plugin and usage documentation.

Export to CSV: Export calculated SPC data (statistics, control lines, and histogram buckets) to a CSV file. Available from the download icon in the statistics table header or by right-clicking the panel and selecting "Download CSV".
Statistics Table: Added a statistics table below the histogram showing descriptive statistics (n, Mean, Std Dev, Min, Max), control limits (LCL, UCL), and process capability indices (Cp, Cpk, Pp, Ppk).
Configurable Table Columns: Choose which columns to display in the statistics table via the panel editor.
Multiple Custom Lines per Series: You can now add more than one custom control line to a single series.
Gaussian Peak (µ) Control Line: New control line type that marks the peak of the fitted Gaussian curve. Uses the Levenberg-Marquardt fitted mean, which may differ from the arithmetic mean for non-normal data.
Histogram Tooltip: Hover over histogram bins to see bucket range and count for each series, similar to Grafana's built-in histogram tooltip. Bell curve fitted values are included when a Gaussian curve is configured.

Added support for Custom Control Lines to pull dynamic values from Feature Series, allowing more flexible histogram configurations.
Added the ability to mark series as Feature Series and hide them from the histogram.
Introduced support for a subgroupSize dashboard variable to control subgroup size across multiple SPC Histogram panels.

Gaussian Curve Functionality: You can now add a Gaussian (normal distribution) curve to your histograms.
Histogram Curve: A new option to plot a smoothed curve along your histogram for better data visualization.
Bug Fixes: We've squashed a few bugs to improve overall performance.
New Documentation: Check out the updated documentation