# XWUIChartForecastConfidenceBand

A forecast confidence-band chart: a fixed-type (`forecastConfidenceBand`) wrapper around `XWUIChart`
that plots a predicted line together with a shaded confidence interval, separating the point forecast
from its plausible range. Pass `series` of `{ name, data: [{ x, y }] }` plus an optional `block`
preset (1-4) and `size` (`sm` / `md` / `lg`); the shared block config also exposes legend,
grid, axis, and tooltip-formatter toggles. Use it for time-series predictions where you need to
communicate both the estimate and its uncertainty.

## Basic Usage

Two named series of monthly values drawn as forecast lines with shaded confidence bands at the medium
size preset.

```example
file: examples/BasicUsage.ts
html: examples/BasicUsage.html
title: Basic Usage
description: Two monthly series rendered as forecast lines wrapped in confidence bands.
```

## Sales Forecast with 95% CI

A monthly point forecast whose Lower/Upper bounds hug the line through history then fan out across the projected months.

```example
file: examples/SalesForecastCI.ts
html: examples/SalesForecastCI.html
title: Sales Forecast with 95% CI
description: Lower/Forecast/Upper sales series with a dollar formatter, legend, and a shaded forecast-horizon region.
```

## Website Traffic Forecast

A weekly visitor projection whose confidence band stays tight early and widens steadily toward later weeks.

```example
file: examples/WebsiteTrafficForecast.ts
html: examples/WebsiteTrafficForecast.html
title: Website Traffic Forecast
description: Lower/Forecast/Upper weekly traffic in thousands, with grid values and week axis labels showing the widening band.
```

```api
```