Include variable in plot title - Google Earth Engine

Question

Is there a way to include a variable as plot title? I'd like my title to be depending on the value of a certain integer (depending here on iC_FC_size).

var text = ee.String('Landsat Mission 4-8 - GEE image availability: ').cat(iC_FC_size)
var options1 = {
  title: 'Landsat Mission 4-8 - GEE image availability Suriname',
  hAxis: {title: 'Year'},
  vAxis: {title: 'Image count'},
  colors: ['red']
}; // options for plotting histogram
var histogram = ui.Chart.feature.histogram({
  features: iC_FC,
  property: 'year',
  minBucketWidth: 1
}).setOptions(options1);
var panel = ui.Panel({
      layout: ui.Panel.Layout.flow('vertical'),
      style: {position: 'bottom-right', height: '500px', width:'350px'}
    }); // create panel for plotting
    ui.root.add(panel);
    panel.widgets().set(0, histogram); // plot the histogram

Wondering if this is even possible?

Regards!

score 1 · Accepted Answer · answered Jun 19 '18 at 15:55

This script includes a variable into the title above a chart:

var ic = ee.ImageCollection('LANDSAT/LT05/C01/T1_SR');

var size= ic.size().getInfo();

var some_title = 'How many LS5 scenes are there? Exactly ' + size+ ' scenes!';

var some_chart = ui.Chart.array.values(ee.Array([1,5,6,8,6]), 0).setOptions({title: some_title});
print(some_chart);

The ".getInfo()" method pulls the value from the server-side to the client-side (i.e. your browser). Then you can construct the string you want as a title with any Javascript commands (e.g. using the "+").

Another way would be to build the string server side and then pull it like this:

var string_size = ee.String(ic.size());

var some_title = ee.String('How many LS5 scenes are there? Exactly ').cat(string_size).cat(' scenes!').getInfo();

score 0 · Answer 2 · answered Aug 01 '18 at 12:24

To add to the answer from Bert Coerver: If you wanted the variable in your plot title to be the name of the polygon from a FeatureCollection being used as ROI in your ImageCollection, this is how you could do it:

var fc = ee.FeatureCollection('ft:some fusion table containing multiple polygons')
    .filter(ee.Filter.eq('name', 'Suriname')); // Here I have already chosen my ROI

// When you are ready to plot:
var area_name = fc.aggregate_array('name').getInfo();
var some_title = 'Name of area: ' + area_name;

var some_chart = ui.Chart.array.values(ee.Array([1,5,6,8,6]), 0).setOptions({title: some_title});
print(some_chart);

Include variable in plot title - Google Earth Engine

2 Answers2