Exporting dataframe - used reduceRegion to sample an image in Google Earth Engine

Question

I am trying to sample the Global Forest Change dataset using randomly drawn points and the reduceRegion function. The way I construct this is:

var sampledPoints = gfc2014_c.reduceRegions({
  collection:points,
  reducer: ee.Reducer.mean()
});

Where gfc2014_c is the GFC datset cropped to sub-Saharan Africa and points are my randomly drawn points. The entire code is here.

I was aiming for a large sample of 1 million pixels. When I try to export in chunks (even chunks as small as 5,000) I get the following error:

Error: image.reduceRegions: Computed value is too large.

What am I doing wrong? I know the GFC dataset is really large, but it must be possible, right?

Answer 1

Based on Justin's comment above and the part of the debugging guide he directed me to, I tried the following:

var sampledPoints = points.map(function(feature) {
  return feature.set(gfc2014.reduceRegion({
    reducer: 'mean',
    geometry: feature.geometry(),
  }));
});

This seems to have worked: I can now export a chunk of 100,000 observations in 5 hours. Thank you Justin!