var image = ee.Image(ee.ImageCollection('LANDSAT/LC8_L1T_TOA')
.filterBounds(roi)
.filterDate('2015-01-01', '2015-12-31')
.sort('CLOUD_COVER')
.first());
print(image);


Map.addLayer(image, {bands: ['B4', 'B3', 'B2'], max: 0.3}, 'image_L8');


var clip = image.clip(table);  //cliping image to shapefile


var newclassified =
vegetation.merge(water).merge(agri_bare).merge(builtarea);
print(newclassified);
var bands = ['B2', 'B3', 'B4', 'B5', 'B6', 'B7', 'B10', 'B11'];


var training = clip.select(bands).sampleRegions({
collection: newclassified,
properties: ['landcover'],
scale: 30
});


var classifier = ee.Classifier.cart().train({
features: training,
classProperty: 'landcover',
inputProperties: bands
});

var classified = clip.select(bands).classify(classifier);

Map.centerObject(newclassified, 11);
Map.addLayer(clip,
{bands: ['B4', 'B3', 'B2'], max: 0.4},
'Landsat image');

Map.addLayer(classified,
{min: 1, max: 4, palette: ['green', 'blue', 'yellow', 'red']},
'classification');