Node.js module to make a random choice among weighted elements of table.
npm install random-weighted-choice
Node.js module to make a random choice among weighted elements of table.
With npm do:
``bash`
npm install random-weighted-choice
Although you can add several times the same id
`js`
var rwc = require("random-weighted-choice");
var table = [
{ weight: 1, id: "item1" }, // Element 1
{ weight: 1, id: "item2" }, // Element 2
{ weight: 4, id: "item3" }, // Element with a 4 times likelihood
{ weight: 2, id: "item1" }, // Element 1, weight added with 2 => 3
];
var choosenItem = rwc(table);
var choosenUnlikely = rwc(table, 100); // The last shall be first
var choosenDeterministically = rwc(table, 0);
It is better to not use the same twice, if you want a temperature other than
the default one (50).
`js`
var rwc = require("random-weighted-choice");
var table = [
{ weight: 1, id: "item1" }, // Element 1
{ weight: 1, id: "item2" }, // Element 2
{ weight: 4, id: "item3" }, // Element with a 4 times likelihood
{ weight: 2, id: "item4" }, // Element 4
{ weight: 2, id: "item5" },
];
var choosenItem = rwc(table);
var choosenUnlikely = rwc(table, 100); // The last shall be first
var choosenDeterministically = rwc(table, 0);
Without temperature (second parameter) or a 50 value, likelihoods are:
`txt`
{ item1: 10%, item2: 10%, item3: 40%, item4: 20%, item5: 20% }
With a temperature value of 100:
`txt`
{ item1: 30%, item2: 30%, item3: 0%, item4: 20%, item5: 20% }
With a temperature value of 0, modified weights are:
`txt`
{ item1: 0, item2: 0, item3: 8, item4: 2, item5: 2 }
Return the id of the chosen item from table.
The table parameter should contain an Array. Each item of that Array mustweight
bean object, with at least and id property.
Weight values are relative to each other. They are integers.
When the sum of the weight values is null, null is returned (can't choose).
When the Array is empty, null` is returned.
More explanations on how it works on Everything2.
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