S2 temporal_series

//This program allows to explore an image collection of Sentinel 2 (with less than 20% cloudy pixels) detected during a period 
var guyane = 
    /* color: #d63000 */
    /* displayProperties: [
      {
        "type": "rectangle"
      }
    ] */
    ee.Geometry.Polygon(
        [[[-53.40798208838487, 4.083804956679912],
          [-53.40798208838487, 3.109329933329487],
          [-52.67189810400987, 3.109329933329487],
          [-52.67189810400987, 4.083804956679912]]], null, false);

function maskS2clouds(image) {
  var qa = image.select('QA60');

  // Bits 10 and 11 are clouds and cirrus, respectively.
  var cloudBitMask = 1 << 10;
  var cirrusBitMask = 1 << 11;

  // Both flags should be set to zero, indicating clear conditions.
  var mask = qa.bitwiseAnd(cloudBitMask).eq(0)
      .and(qa.bitwiseAnd(cirrusBitMask).eq(0));

  return image.updateMask(mask);
}
var rgbVis = {
  min: 0.0,
  max: 0.3,
  bands: ['B8', 'B4', 'B2'],
};
var s2 = ee.ImageCollection('COPERNICUS/S2')
                  .filterDate('2018-08-01', '2018-10-31')
                  .filterBounds(guyane)
                  .filter(ee.Filter.lt('CLOUDY_PIXEL_PERCENTAGE', 20))
                  // Pre-filter to get less cloudy granules.
                  .map(maskS2clouds)
                  .limit(15)


function addImage(image) { // display each image in collection
  var id = image.id
  var image = ee.Image(image.id)
  Map.addLayer(image.divide(10000),rgbVis)
}

s2.evaluate(function(s2) {  // use map on client-side
  s2.features.map(addImage)
})
var slider = ui.Slider();
slider.onSlide(function(value) {
  var int_value = value * (Map.layers().length() - 1) >> 0;
  Map.layers().get(int_value).setOpacity(1);
  for (var i = int_value + 1; i < Map.layers().length(); i++) {
    Map.layers().get(i).setOpacity(0);
}
});
print("balayez pour explorer la série d'images (après chargement)",slider);