1

I am trying to define a set of colours by month on a ui.Chart.image.series, however, after adding the .style line, no changes are made. I would like to have a different bar color for each month, the palette should repeats over different years.

My code so far looks like this:


var dataset = ee.ImageCollection('TRMM/3B43V7')
                  .filter(ee.Filter.date('1998-01-01', '2019-06-30'));
var precipitation = dataset.select('precipitation');
var precipitationVis = {
  palette: ['blue', 'purple', 'cyan', 'green', 'yellow', 'red'],
};
Map.setCenter(6.746, 46.529, 3);
Map.addLayer(precipitation, precipitationVis, 'Precipitation');


// Define a region of interest as a buffer around a point.
var geom = ee.Geometry.Point(-74.08384, 9.42503).buffer(500);

// Create and print the chart.
var mean_prec_chart = ui.Chart.image.series(precipitation, geom, ee.Reducer.mean(), 12);
mean_prec_chart.setChartType('ColumnChart');
mean_prec_chart.style({color:['blue','red','green','brown']});
print(mean_prec_chart);

Resulting chart

2

You will need to rework the data calculated in ui.Chart.image.series() into a feature collection. Then you will add a property for each different month and you can plot each month using ui.Chart.feature.groups().

// put the data similar as presented in the chart above in a featureCollection
var featsPrecipitation = ee.FeatureCollection(precipitation.map(function(image){
  var precip = image.reduceRegion(ee.Reducer.mean(),geom, 12);
  var groupProp = image.date().format('MM');
  return ee.Feature(null, precip).copyProperties(image, image.propertyNames())
                    .set('month', groupProp);
}));
print(featsPrecipitation)

var mean_prec_chart = ui.Chart.feature.groups(featsPrecipitation, 
                                              'system:time_start', 'precipitation', 'month');
mean_prec_chart.setChartType('ColumnChart')
// by default, all months will have another colour. But you can set them by your own
// mean_prec_chart.style({color:['blue','red','green','brown']});
print(mean_prec_chart);

The chart will visually look a bit different due to the distance between the bars, but the data is similar.

link code

| improve this answer | |
  • Thanks @Kuik, this is what I was looking for, however, I am struggling now to make the bars a bit wider. – Oscar Oct 2 '19 at 13:41
  • I didn't succeed either. Maybe ask on the forum. – Kuik Oct 3 '19 at 7:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.