Google Earth Engine Chart Error

Question

I'm trying to generate a chart of NDVI bands from 2000 to 2020, but I am running into an error:

Error generating chart: Error in map(ID=19990509):
Image.reduceRegion: The default WGS84 projection is invalid for aggregations.
Specify a scale or crs & crs_transform.

How can I fix this? Here is my current code:

Map.setCenter(-75.52247, -12.73755, 13);

var onePoint = ee.Geometry.Point([-75.52247, -12.73755]);

Map.setCenter(-75.52247, -12.73755,15);

var bufferedPoint = onePoint.buffer(100);

Map.addLayer(bufferedPoint);

var collection = ee.ImageCollection("LANDSAT/LE07/C01/T1_32DAY_NDVI").select('NDVI');

var bufferedPoint = ee.Geometry.Point(-75.52247, -12.73755).buffer(100);

print(ui.Chart.image.series(collection, bufferedPoint, ee.Reducer.mean()));

Map.setCenter(-75.52247, -12.73755);

Answer 1

As you can see in error message, it is mandatory to specify a scale or crs & crs_transform. In my case, I arbitrarily selected 1000 as scale and, your modified code looks as follows:

Map.setCenter(-75.52247, -12.73755, 13);
    
var onePoint = ee.Geometry.Point([-75.52247, -12.73755]);
    
Map.setCenter(-75.52247, -12.73755,15);
    
var bufferedPoint = onePoint.buffer(100);
    
Map.addLayer(bufferedPoint);
    
var collection = ee.ImageCollection("LANDSAT/LE07/C01/T1_32DAY_NDVI").select('NDVI');
  
print("size", collection.size());
    
var bufferedPoint = ee.Geometry.Point(-75.52247, -12.73755).buffer(100);
    
print(ui.Chart.image.series(collection, bufferedPoint, ee.Reducer.mean(), 1000));

After running it in GEE code editor, chart is printed without any error.