Random forest error on GEE

Question

I have a problem with random forest classification, receiving an error message after inputting the training dataset. My code includes a long preprocessing for Sentinel1 and Sentinel2, but here I'll simply summarize the code here (starting from line 248) GEE code: https://code.earthengine.google.com/3e844f7bd2cfa702709853fc78497dc4

//input the training data
var trainingData = ee.FeatureCollection('projects/ee-2023swedenagb/assets/Swe2017sample_ROI1');

//using sampleRegion to extract the values from S1 and S2 image
var s2_sample = s2L2017c1_6_Veg.sampleRegions({
  collection: trainingData,
  scale: 10,
  properties: ['AGB_DW'],
  projection: 'EPSG:3006'
});
print(s2_sample)

var s1_sample = s1L20171_6_predb.sampleRegions({
  collection: trainingData,
  scale: 10,
  properties: ['AGB_DW'],
  projection: 'EPSG:3006'
});
print(s1_sample)

//there are 211 pixels being extracted as the training data separately from S1 and S2
//merge the output from sampleRegion S1, S2 
var S1S2_2017_sample = s2_sample.merge(s1_sample)
print(S1S2_2017_sample)
//now there are 422 pixels being printed, which means the merge() function merges the S1 S2 but in different rows of data (but the 211 pixels are the same)


//using addBands function to combine the whole S1, S2 images
var S1_2017_VV = s1L20171_6_predb.select('VV');
var S1_2017_VH = s1L20171_6_predb.select('VH');

var S1S2_2017 = s2L2017c1_6_Veg.addBands(S1_2017_VV).addBands(S1_2017_VH);
print(S1S2_2017);

//selecting all the bands I need to input into the random forest model
var variables2017 = S1S2_2017.select(['VV','VH','B1','B2','B3','B4','B5','B6','B7','B8','B8A','B9','B11','B12','NDVI','RVI','EVI','NDVIn','NDVIre','DVI','Vigreen','GNDVI','SAVI','MSAVI','ARVI','NDI45']);

//using random forest as the first trial to calculate the image, also where the error occured
var classifier = ee.Classifier.randomForest(10).train({
  feature: S1S2_2017_sample,
  classProperty: 'AGB_DW',
  inputProperties: variables2017
})

var classified = variables2017.classify(classifier)
Map.addLayer(classified)

and the error says

Line 315: Required argument (features) missing to function: Classifier.train(classifier, features, classProperty, inputProperties, subsampling, subsamplingSeed)

Trains the classifier on a collection of features, using the specified numeric properties of each feature as training data. The geometry of the features is ignored.

I learn this method from a video from Google Earth (https://www.youtube.com/watch?v=6KIJB4A6VbI), but I'm not really sure why the error occurred.

Answer 1

After searching for helps from people, I learn that in this case, I should use the sampleRegion function after addbands, then it is required to use the new version of RF model, which is Classifier.randomForest -> Classifier.smileRandomForest. The link below is the announcement of the code update from GEE: https://groups.google.com/g/google-earthengine-announce/c/rCu4FP_Cn08/m/DqC192X9BAAJ?fbclid=IwAR3zvvG3CHzsHrhrTQspifwsNnk8wIBAgK_C3OjQMn_pvB4tS7ULa7p0qdc

var trainingData = ee.FeatureCollection('projects/ee-2023swedenagb/assets/Swe2017sample_ROI1');

//merge S1 and S2 data(image) in terms of their bands


var S1_2017_VV = s1L20171_6_predb.select('VV');
var S1_2017_VH = s1L20171_6_predb.select('VH');

var S1S2_2017 = s2L2017c1_6_Veg.addBands(S1_2017_VV).addBands(S1_2017_VH);
print(S1S2_2017);


var s1s2_sample = S1S2_2017.sampleRegions({
  collection: trainingData,
  scale: 10,
  properties: ['AGB_DW'],
  projection: 'EPSG:3006'
});
print(s1s2_sample)

var variables2017 = S1S2_2017.select(['VV','VH','B1','B2','B3','B4','B5','B6','B7','B8','B8A','B9','B11','B12','NDVI','RVI','EVI','NDVIn','NDVIre','DVI','Vigreen','GNDVI','SAVI','MSAVI','ARVI','NDI45']);

var classifier = ee.Classifier.smileRandomForest(10).train({
  features: s1s2_sample,
  classProperty: 'AGB_DW',
  inputProperties: variables2017
})