GEE, scatter plot. ERROR: array length mismatch

Question

In Google Earth Engine i am trying to find scatter between elevation and occurrence but i am getting common number of array vectors

'''

var data=ee.Image("JRC/GSW1_3/GlobalSurfaceWater").clipToBoundsAndScale(geometry);
var dem=ee.Image("USGS/SRTMGL1_003").clipToBoundsAndScale(geometry);
var mask = data.select(['occurrence']).gt(0);
var data = data.updateMask(mask);
var dem = dem.updateMask(mask);
Map.addLayer(dem,'','dem');
Map.addLayer(data,'','data');
Map.addLayer(mask,'','Mask');
var pixelValsY = data.reduceRegion(
    {reducer: ee.Reducer.toList(), geometry: geometry, scale: 30});
    
var pixelValsX = dem.reduceRegion(
    {reducer: ee.Reducer.toList(), geometry: geometry, scale: 30});
    
var x = ee.List(pixelValsX.get('elevation'));
var y = ee.List(pixelValsY.get('occurrence'));

var chart = ui.Chart.array.values({array: y, axis: 0, xLabels: x});
print(chart);
'''

Erroe msg is 'Error generating chart: xLabels must be the same length as the 1-D vectors from the array.'

please help me out

Answer 1

Worked when specificying the crs field in .reduceRegion so that the two images are in a common projection. Example:

var pixelValsY = data.reduceRegion(
    {reducer: ee.Reducer.toList(), geometry: geometry, scale: 30});
    
var pixelValsX = dem.reduceRegion(
    {reducer: ee.Reducer.toList(), geometry: geometry, scale: 30, crs: data.projection()});

Alternatively,

var pixelVals = data.addBands(dem).reduceRegion(
    {reducer: ee.Reducer.toList(), geometry: geometry, scale: 30})
var x = ee.List(pixelVals.get('elevation'));
var y = ee.List(pixelVals.get('occurrence'));

In this second example (two less lines of code), it appears that stacking the images sets them to some sort of common projection.