Proprietary extension to Mozilla rr by rr lead coder Robert O'Callahan et. al, started in 2016 after he quit Mozilla.
TODO what does it add to
rr?A quantum algorithm that is thought to be more likely to be useful in the NISQ era of quantum computing.
University of Cambridge students, CanTabBridgeans.
- phaser/hello.html: a minimal hello world adapted from web.archive.org/web/20230323212804/https://phaser.io/tutorials/getting-started-phaser3/part5. Not an actual game strictly speaking though, just shows the phaser logo bouncing around the screen.
- phaser/hello-game.html: an actually hello world game where you have to collect stars and avoid bombs.Based on labs.phaser.io/index.html?dir=games/firstgame/&q=:
- finished version: labs.phaser.io/view.html?src=src/games/firstgame/part10.js
- corresponding tutorial: web.archive.org/web/20230323210501/https://phaser.io/tutorials/making-your-first-phaser-3-game/part10.
tipitaka.fandom.com/wiki/Puggala-Pannatti-Chap.2:
He who stores up whatever he gets and he who gives away whatever he gets - these two persons are hard to satisfy.
Let's try it on SQLite 3.40.1, Ubuntu 23.04. Data setup:
sqlite3 tmp.sqlite 'create table t(x integer, y integer)'
sqlite3 tmp.sqlite <<EOF
insert into t values
(0, 0),
(1, 1),
(2, 2),
(3, 3),
(4, 4),
(5, 5),
(6, 6),
(7, 7),
(8, 8),
(9, 9),
(10, 10),
(11, 11),
(12, 12),
(13, 13),
(14, 14),
(15, 15),
(16, 16),
(17, 17),
(18, 18),
(19, 19),
(2, 18)
EOF
sqlite3 tmp.sqlite 'create index txy on t(x, y)'For a bin size of 5 ignoring empty ranges we can:which produces the desired:
sqlite3 tmp.sqlite <<EOF
select
floor(x/5)*5 as x,
floor(y/5)*5 as y,
count(*) as cnt
from t
group by 1, 2
order by 1, 2
EOF0|0|5
0|15|1
5|5|5
10|10|5
15|15|5And to consider empty ranges we can use SQL which outputs the desired:
genenerate_series + as per stackoverflow.com/questions/72367652/populating-empty-bins-in-a-histogram-generated-using-sql:sqlite3 tmp.sqlite <<EOF
select x, y, sum(cnt) from (
select
floor(x/5)*5 as x,
floor(y/5)*5 as y,
count(*) as cnt
from t
group by 1, 2
union
select *, 0 as cnt from generate_series(0, 15, 5) inner join (select * from generate_series(0, 15, 5))
)
group by x, y
EOF0|0|5
0|5|0
0|10|0
0|15|1
5|0|0
5|5|5
5|10|0
5|15|0
10|0|0
10|5|0
10|10|5
10|15|0
15|0|0
15|5|0
15|10|0
15|15|5Similar to SQL subquery, but with some differences: stackoverflow.com/questions/706972/difference-between-cte-and-subquery
rm -f tmp.sqlite
sqlite3 tmp.sqlite 'create table t(i integer)'
sqlite3 tmp.sqlite 'insert into t values (1), (2)'
sqlite3 tmp.sqlite 'with mycte as ( select * from t ) delete from mycte where i = 1'
sqlite3 tmp.sqlite 'select * from t'How to implement Nested set model in SQL:
- stackoverflow.com/questions/192220/what-is-the-most-efficient-elegant-way-to-parse-a-flat-table-into-a-tree/42781302#42781302 contains the correct left/size representation and update queries, which makes it much easier to maintain the tree without having to worry about the sizes of siblings which are constant
- stackoverflow.com/questions/192220/what-is-the-most-efficient-elegant-way-to-parse-a-flat-table-into-a-tree/194031#194031 amazing ASCII art representations of the structure. Unfortunately uses a wonky left/right representation, rather than the much more natural left/size representation from the other post
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