Time Series Charts

Use ui.Chart.image.series() to print a time series, as a line chart by default, within a region:

// Load Landsat 8 top-of-atmosphere (TOA) input imagery.
var collection = ee.ImageCollection('LANDSAT/LC08/C01/T1_TOA').select('B[1-7]');

// Define a region of interest as a buffer around a point.
var geom = ee.Geometry.Point(-122.08384, 37.42503).buffer(500);

// Create and print the chart.
print(ui.Chart.image.series(collection, geom, ee.Reducer.mean(), 30));

Note that the arguments to ui.Chart.image.series() include an ImageCollection, a region, a Reducer and a scale. Optionally, specify coordinates for the X-axis. If these are not specified, the system:time_start property will be used. (Make sure input imagery has this property or specify the property to use.) The result should look something like Figure 1.

Figure 1. Time series of image collection data at a point in Mountain View, California.