54 lines
1.5 KiB
JavaScript
54 lines
1.5 KiB
JavaScript
/**
|
|
* Decimal adjustment of a number.
|
|
*
|
|
* @param {String} type The type of adjustment.
|
|
* @param {Number} value The number.
|
|
* @param {Integer} exp The exponent (the 10 logarithm of the adjustment base).
|
|
* @returns {Number} The adjusted value.
|
|
*/
|
|
var decimalAdjust = exports.decimalAdjust = function(type, value, exp) {
|
|
// If the exp is undefined or zero...
|
|
if (typeof exp === 'undefined' || +exp === 0) {
|
|
return Math[type](value);
|
|
}
|
|
value = +value;
|
|
exp = +exp;
|
|
// If the value is not a number or the exp is not an integer...
|
|
if (isNaN(value) || !(typeof exp === 'number' && exp % 1 === 0)) {
|
|
return NaN;
|
|
}
|
|
// Shift
|
|
value = value.toString().split('e');
|
|
value = Math[type](+(value[0] + 'e' + (value[1] ? (+value[1] - exp) : -exp)));
|
|
// Shift back
|
|
value = value.toString().split('e');
|
|
return +(value[0] + 'e' + (value[1] ? (+value[1] + exp) : exp));
|
|
}
|
|
|
|
module.exports = {
|
|
round10: function(value, exp) {
|
|
return decimalAdjust('round', value, exp);
|
|
},
|
|
floor10: function(value, exp) {
|
|
return decimalAdjust('floor', value, exp);
|
|
},
|
|
ceil10: function(value, exp) {
|
|
return decimalAdjust('ceil', value, exp);
|
|
},
|
|
};
|
|
|
|
module.exports.polyfill = function() {
|
|
// Decimal round
|
|
if (!Math.round10) {
|
|
Math.round10 = module.exports.round10;
|
|
}
|
|
// Decimal floor
|
|
if (!Math.floor10) {
|
|
Math.floor10 = module.exports.floor10;
|
|
}
|
|
// Decimal ceil
|
|
if (!Math.ceil10) {
|
|
Math.ceil10 = module.exports.ceil10;
|
|
}
|
|
};
|