Calculating column mean of array or list using Google Earth Engine

Question

I want to calculate the column mean of the following set of data as the result of 1 row and 7 columns.

Which functions should I use in Google Earth Engine or should I write an extra function?

var data=[['1','2','3','4','5','6','7'],
              ['8','9','10','11','12','13','14'],            
       ['15','16','17','18','19','20','21']];

Answer 1

One way is:

var data=ee.Array([[1,2,3,4,5,6,7], [8,9,10,11,12,13,14],
[15,16,17,18,19,20,21]]);

var data2 = data.transpose().toList();
print(data2)

var mean = data2.map(function(lis) {
  return ee.List(lis).reduce(ee.Reducer.mean());
});
print(mean)