I've wrote a code for modis ndvi timeseries(code below). But it returns error in chart creating (ui.Chart.image.seriesByRegion) : Error generating chart: Invalid argument specified for ee.Number(): system:time_start
var regions = ee.FeatureCollection([
ee.Feature( // forest.
ee.Geometry.Rectangle(geometry), {label: 'forest'}),
ee.Feature( // crop.
ee.Geometry.Rectangle(geometry2), {label: 'crop'})
]) ;
var modis = ee.ImageCollection("MODIS/006/MOD13Q1")
.filterDate("2000-01-01","2017-12-31");
var mod13 = modis.map(function(img){
var id = img.id();
img = img.select("NDVI").rename(id);
return img.multiply(0.0001)
.copyProperties(img,['system:time_start','system:time_end']);
});
print(mod13);
var timeseries = ui.Chart.image.seriesByRegion(
mod13,regions,ee.Reducer.mean(),250,'system:time_start','label')
.setChartType('ScatterChart')
.setOptions({
title : 'vegetation series',
xAxis : {title : 'time'},
yAxis : {title : 'NDVI'},
lineWidth : 1,
pointSize : 2,
series : {
0 : {color : 'red'},
1 : {color : 'green'}
}});
print(timeseries);