Weighted randomisation.

[Jacqui1811]

I am trying to do a flashcard project to help learn a langauge and I have all the words in a category in a nice array in the format :

key -> combination_id , value -> 1
key -> eng_word, value -> cat
key -> for-word, value -> neko
key -> skill_level, value -> 3

I have a lot of these in the array and want to randomly pick one from it BUT I want to be able to pick those with the lower skill level (1) more often than those with a skill level of (2) and level (3) even less.

Can anyone help ?

Thanks.
Jacqui.

 

[schizoman]

How about a 2-dimensional array? Below isn’t super elegant, but I think it would work.


$lvl1=array
(
key -> combination_id , value -> 1
key -> eng_word, value -> cat
key -> for-word, value -> easy
);

$lvl2=array
(
key -> combination_id , value -> 1
key -> eng_word, value -> cat
key -> for-word, value -> medium
);


$lvl3=array
(
key -> combination_id , value -> 1
key -> eng_word, value -> cat
key -> for-word, value -> hard
);

$word_list=array ($lvl1,$lvl2,$lvl3);

// this assumes lvl 3 10% of the time, lvl 2 40% of the time and lvl1 50% of the time
function pickWord()
{
global $word_list

$level=rand(1,10);
switch ($level)
{
case 1:
$which=rand(0,count($word_list[2]-1);
$hardness=2;
break;
case >4:
$which=rand(0,count($word_list[0]-1);
break;
$hardness=0;

default:
$which=rand(0,count($word_list[1]-1);
$hardness=1;
break;
}
return ($word_list[$hardness][$which]
}