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ui.Chart.image.doySeriesByRegion

Page Summary

Theui.Chart.image.doySeriesByRegion function generates a chart from an ImageCollection.
The chart plots the derived value of a specified band for different regions across the day of year.
The chart's x-axis represents the day of year, the y-axis represents the derived band value, and the series represent the regions.
The function returns aui.Chart and takes arguments including the ImageCollection, band name, regions, and optional reducers and scale.

Generates a Chart from an ImageCollection. Plots the derived value of the given band in different regions at each day-of-year.

- X-axis: Day of year (startDay to endDay, defaults to 1 to 366).

- Y-axis: Derived band value (reduced within the region and across years).

- Series: Regions.

Returns a chart.

Usage	Returns
`ui.Chart.image.doySeriesByRegion(imageCollection, bandName, regions,regionReducer,scale,yearReducer,seriesProperty,startDay,endDay)`	ui.Chart

Argument	Type	Details
`imageCollection`	ImageCollection	The ImageCollection to chart.
`bandName`	Number\|String	The name of the band to chart.
`regions`	Feature\|FeatureCollection\|Geometry\|List<Feature>\|List<Geometry>	The regions to reduce.
`regionReducer`	Reducer, optional	Reducer for aggregating band values within the region. Must return a single value. Defaults to ee.Reducer.mean().
`scale`	Number, optional	Scale to use with the region reducer in meters.
`yearReducer`	Reducer, optional	Reducer for aggregating band values across years (for a given day of year). Must return a single value. Defaults to ee.Reducer.mean().
`seriesProperty`	String, optional	Property of features in opt_regions to be used for series labels. Defaults to 'system:index'.
`startDay`	Number, optional	Day of year to start the series. Must be between 1 and 366.
`endDay`	Number, optional	Day of year to end the series. Must be between startDay and 366.

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Last updated 2025-07-08 UTC.