Package edu.cnu.mdi.splot.pdata

package edu.cnu.mdi.splot.pdata

Data-model classes for the splot plotting library.

This package contains the core data abstractions that back all plots in splot, including:

• ACurve – the abstract base class for all curves
• Curve – standard XY curves with optional Y-errors
• HistoCurve – histogram-backed curves
• Supporting data containers such as DataColumn and HistoData

Responsibilities

Classes in this package are responsible for:

• Storing and managing curve and histogram data
• Providing consistent snapshots for rendering
• Managing cached derived artifacts such as fit results and splines
• Notifying listeners when data or style changes occur

Threading Model

splot is built on Swing. As a result, all notifications that may lead to UI updates (such as repaint requests) must occur on the Swing Event Dispatch Thread (EDT).

To support modern streaming and data-acquisition use cases, Curve and HistoCurve provide thread-safe data addition methods:

• add(...) and addAll(...) may be called from any thread
• Off-EDT calls enqueue data into lock-free staging queues
• Queued data are later applied on the EDT in bounded batches
• A single consolidated data-change notification is fired per batch

This design prevents repaint storms while preserving strict Swing correctness.

Explicit Streaming Control

For advanced use cases, curves also expose an explicit staging API:

• enqueue(...) – thread-safe, no immediate mutation or notification
• drainPendingOnEDT(...) – EDT-only, applies queued data in bulk

This allows applications to centralize draining (for example, via a single Swing timer) or implement custom backpressure strategies.

Fitting and Derived Artifacts

Fit results, spline caches, and other derived artifacts are invalidated when data or relevant style parameters change. Re-computation is typically triggered lazily during rendering via doFit(...).

All fitting and artifact management follows the same EDT discipline as data updates.

Design Philosophy

This package deliberately separates:

• Data ownership and consistency (this package)
• Rendering and interaction (view and canvas layers)

While some implementation details intentionally blur strict MVC boundaries for performance and simplicity, the overall design favors robustness, predictability, and ease of use in interactive scientific applications.

Class	Description
ACurve	Base class for all plottable curves (XY curves, histogram curves, strip-chart curves, etc.).
ACurve.PendingQueue<T>	A reusable pending-queue helper for streaming/DAQ scenarios.
Curve	A standard XY curve consisting of X, Y, and an optional Y-error column (E).
CurveChangeListener	Listener for changes to an ACurve.
CurveChangeType	Types of changes that can occur to a curve.
DataChangeListener	A listener for changes to the data.
DataColumn	A named numeric column used by sPlot datasets.
DataList	Named list of Double values with cached min/max tracking.
FitVectors	Immutable fit vectors (x, y, optional weights) used by the Apache least-squares fitters.
Histo2DData	Container class for 2D histogram (heatmap) data.
HistoCurve	Histogram-backed curve that integrates HistoData into the ACurve fitting and drawing framework.
HistoData	Container for 1D histogram data.
HistoDrawingUtils	Stateless utility class for rendering-related histogram helpers.
HistoFitPrep	Stateless utility class for histogram fit preparation.
HistoFitPrep.FitWindowData	A FitVectors that also records which peak bin and window were actually used.
PlotData	A lightweight, UI-agnostic container for the data backing a plot.
PlotDataException	Checked exception raised when a plot dataset cannot be constructed.
PlotDataType	Types of data sets
Snapshot	A snapshot of data points.
StripChartCurve	Backing data model for a strip chart / time-series plot.