mysql - Sorting by preferred average value -


i'm making game involves people downloading , rating user-created maps. have option upvote/downvote map if like/dislike it, rate difficult on scale of 1-10.

in map browser, have option sort maps highest rated. done using laplace smoothing factors both number of upvotes total number of ratings sorting, sorting (upvotes + 1)/(numratings + 2). works fine.

now, there's option sort preferred difficulty, people can choose value 1-10, , sort maps how close average difficulty rating preferred rating. @ first sorting abs(preferred_difficulty - average_difficulty), didn't factor in number of ratings. right i'm using ((numratings + 1) * (10 - abs(average_difficulty - preferred_difficulty)) + 1) / (numratings + 1.5) out of sheer trial , error, kinda works, number of ratings outweighs preferred difficulty , results strange.

this need - can't figure out how sort smallest difference between preferred , average difficulty while incorporating number of ratings mix, since want low difficulty delta high rating count best result instead of high upvote count high rating count, ratings.

for example, if data:

avgdifficulty      numratings       6.0                 1       4.0                25       6.8                 4       6.2                 3       6.5                20       6.2                 1       6.4                 3

and chooses preferred difficulty of 6.4, i'd want sort this:

avgdifficulty      numratings       6.5                20        6.4                 3          6.2                 3       6.8                 4       6.2                 1         6.0                 1       4.0                25

basically want results close preferred difficulty @ top, i'd rather show results 0.1 off lots of ratings on exact matches few ratings. understand getting "right" results may not concrete in case, i'm looking starting point.

thanks help!

you have bit of nebulous question. need way combine rating , count. basic query is:

order abs(avg_difficulty - 6.4)

but, want include count well. can define fixed band @ top , order these ranking:

order (case when abs(avg_difficulty - 6.4) < 0.1) numratings end) desc,          abs(avg_difficulty - 6.4)

this expression combines 6.3 - 6.5 in 1 group , sorts these number of ratings. second key sorts else difference.


Comments

Post a Comment

Popular posts from this blog

c# - Validate object ID from GET to POST -

i have method allows user access comment have made on site. have post method lets them update comment. my normal solution send entire comment model through, let them update it, update on database when post back. involve sending commentid through in hiddenfor , can manipulated. how can verify commentid sent in get method same i'm getting in post , not able alter comment wish? how can verify commentid sent in method same i'm getting in post? basically have validate following things in post - user logged-in user. authenticated users post comments. commentid in post , should valid commentid , should present in database. userid associated logged-in user should same userid associated comment . comment should contain userid column, can check @ time of update. to make sure update happens comment has been sent in get - hold commentid in session , in post action compare commentid value in session .
Read more

node.js - Custom Model Validator SailsJS -

when using custom model validator checks record within model. return within spread doesn't seem end control flow. //post.js model /** * custom validator **/ types: { isuservalid: function(user_id) { var promise = require('bluebird'); promise.all([ user.findone({id: user_id}) ]) .spread(function(user) { console.log(user); if (user === null || user === undefined) { console.log('failed'); return false; }else{ console.log('passed'); return true; } }); } }, my response standard validation failed response. { "error": "e_validation", "status": 400, "summary": "1 attribute invalid", "model": "post", "invalidattributes": { "owner": [ { "rule": "isuservalid", ...
Read more

php - Find a regex to take part of Email -

i have following emails need extract part from: bestellnummer xxx: 1 von xxx, 1er pack ------------- anfang der nachricht ------------- foo bar baz foo bar baz // <<<<< need text here ------------- ende der nachricht ------------- ------------- anfang der nachricht ------------- foo bar baz foo bar baz ------------- ende der nachricht ------------- there 0 unlimited occurences of ------------- anfang der nachricht ------------- ------------- ende der nachricht ------------- and i'm able extract first part regex: $re = "/------------- .*? -------------.?(.*?).?------------- .*? -------------/s"; but, i'm quite new on learning regex, i'm pretty sure there must better regex extract part (foo bar baz foo bar baz) of text between ------------- anfang der nachricht ------------- ------------- ende der nachricht ------------- as can in different languages, i'm using .? to match between hyphens. i...
Read more