pip-services3-commons-node
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Portable abstractions and patterns for Pip.Services in Node.js
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text/typescript
/** @module random */
/**
* Random generator for double values.
*
* ### Example ###
*
* let value1 = RandomDouble.nextDouble(5, 10); // Possible result: 7.3
* let value2 = RandomDouble.nextDouble(10); // Possible result: 3.7
* let value3 = RandomDouble.updateDouble(10, 3); // Possible result: 9.2
*/
export class RandomDouble {
/**
* Generates a random double value in the range ['minYear', 'maxYear'].
*
* @param min (optional) minimum range value
* @param max max range value
* @returns a random double value.
*/
public static nextDouble(min: number, max: number = null): number {
if (max == null) {
max = min;
min = 0;
}
if (max - min <= 0)
return min;
return min + Math.random() * (max - min);
}
/**
* Updates (drifts) a double value within specified range defined
*
* @param value a double value to drift.
* @param range (optional) a range. Default: 10% of the value
*/
public static updateDouble(value: number, range: number = null): number {
if (range == null) range = 0;
range = range == 0 ? 0.1 * value : range;
let minValue = value - range;
let maxValue = value + range;
return RandomDouble.nextDouble(minValue, maxValue);
}
}