Checkpoint before I break everything

Makefile

@@ -515,6 +515,37 @@ join-test: tippecanoe tippecanoe-decode tile-join
 	cmp tests/ne_110m_ocean/join/joined.mbtiles.json.check tests/ne_110m_ocean/join/joined.mbtiles.json
 	rm -f tests/ne_110m_ocean/join/ocean.mbtiles tests/ne_110m_ocean/join/countries.mbtiles tests/ne_110m_ocean/join/joined.mbtiles tests/ne_110m_ocean/join/joined.mbtiles.json.check
 
+accumulate-test:
+	# there are 144 features with POP1950 in the original dataset
+	test `grep '"POP1950": [0-9]' tests/ne_110m_populated_places_nulls/in.json | wc -l` == 144
+	# and 99 without it
+	test `grep '"POP1950": null' tests/ne_110m_populated_places_nulls/in.json | wc -l` == 99
+	./tippecanoe -yNAME -yPOP1950 -q -z3 -r1.75 -b0 -f -e tests/pbf/accum.dir --accumulate-numeric-attributes --set-attribute clustersize:1 --accumulate-attribute clustersize:sum --retain-points-multiplier 3 tests/ne_110m_populated_places_nulls/in.json
+	# at this drop rate, there are 6 points at z0 that have no POP1950s clustered onto them....
+	echo test `./tippecanoe-decode -c tests/pbf/accum.dir/0/0/0.pbf 0 0 0 | grep -v 'tippecanoe:count:POP1950' | wc -l` == 6
+	# two of which have no POP1950 at all
+	echo test `./tippecanoe-decode -c tests/pbf/accum.dir/0/0/0.pbf 0 0 0 | grep -v 'POP1950' | wc -l` == 2
+	# plus 40 that are clustered
+	echo test `./tippecanoe-decode -c tests/pbf/accum.dir/0/0/0.pbf 0 0 0 | grep 'tippecanoe:count:POP1950' | wc -l` == 40
+	# the 40 clustered POP1950s have a total count of 140
+	echo test `./tippecanoe-decode -c tests/pbf/accum.dir/0/0/0.pbf 0 0 0 | grep 'tippecanoe:count:POP1950' | sed 's/.*"tippecanoe:count:POP1950": //' | awk '{sum += $$1} END {print sum}'` == 140
+	# we have already established that there are 4 bare POP1950s
+	# which makes a total of 144, which is the total count expected
+	#
+	# on to the sums:
+	# in the original data set, the POP1950s that are present add up to 161590
+	test `grep '"POP1950": [0-9]' tests/ne_110m_populated_places_nulls/in.json | sed 's/.*"POP1950": //' | awk '{sum += $$1} END {print sum}' ` == 161590
+	# in the z0 tile, the clustered POP1950s add up to 146370
+	test `./tippecanoe-decode -c tests/pbf/accum.dir/0/0/0.pbf 0 0 0 | grep 'tippecanoe:sum:POP1950' | sed 's/.*"tippecanoe:sum:POP1950": //' | awk '{sum += $$1} END {print sum}'` == 146370
+	# and the non-clustered ones add up to 15220
+	test `./tippecanoe-decode -c tests/pbf/accum.dir/0/0/0.pbf 0 0 0 | grep -v 'tippecanoe:sum:POP1950' | grep POP1950 | sed 's/.*"POP1950": //' | awk '{sum += $$1} END {print sum}'` == 15220
+	# which is the correct 161590
+	#
+	# OK, so do these still hold after megatile filtering?
+	./tippecanoe-overzoom --accumulate-numeric-attributes -m -o tests/pbf/accum-0-0-0.pbf tests/pbf/accum.dir/0/0/0.pbf 0/0/0 0/0/0
+	# Now there are N features with POP1950 clusters
+	echo test `./tippecanoe-decode -c tests/pbf/accum-0-0-0.pbf 0 0 0 | grep 'tippecanoe:count:POP1950' | wc -l` == 40
+
 join-filter-test: tippecanoe tippecanoe-decode tile-join
 	# Comes out different from the direct tippecanoe run because null attributes are lost
 	./tippecanoe -q -z0 -f -o tests/feature-filter/out/all.mbtiles tests/feature-filter/in.json