# init(x:yStart:yEnd:) Creates an area mark that plots values with a vertical interval. ``` nonisolated init(x: PlottableValue, yStart: PlottableValue, yEnd: PlottableValue) where X : Plottable, Y : Plottable ``` ## Parameters `x` The horizontal position for the mark. `yStart` The starting vertical position for the mark. `yEnd` The ending vertical position for the mark. ## Discussion Use this initializer to create a range area chart with vertical intervals. For example you can create a region that encompasses all the temperatures over the course of a day, across a number of days: ``` Chart(data) { day in AreaMark( x: .value("Date", day.date), yStart: .value("Minimum Temperature", minimumTemperature), yEnd: .value("Maximum Temperature", day.maximumTemperature) ) } ```  If you want to plot values that have a horiztonal interval, use [`init(xStart:xEnd:y:)`](/documentation/Charts/AreaMark/init(xStart:xEnd:y:)) instead. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)