[test2(1:numel(datarawsnan)).Geometry] = deal('MultiPoint');
t = num2cell(datarawsnan);
[test2.id] = deal(t{:});
t = num2cell(lonn);
[test2.lon] = deal(t{:});
t = num2cell(latt);
[test2.lat] = deal(t{:});
shapewrite(test2, 'test2');
Alternately,
test2 = struct('Geometry', 'Multipoint', 'id', num2cell(datarawsnan), 'lon', num2cell(lonn), 'lat', num2cell(latt));
shapewrite(test2, 'test2');
Though possibly you would have to change the shapewrite call to be
shapewrite(test2(:), 'test2');
The first version of the code using the explicit assignments would create a structure vector, whereas the second version of the code, using struct(), would create a structure array the same shape as your arrays.
