Math.f16round()
Math.f16round()
静态方法返回数字最接近的 16 位半精度 浮点表示形式。
¥The Math.f16round()
static method returns the nearest 16-bit half precision float representation of a number.
Try it
语法
参数
返回值
¥Return value
doubleFloat
最接近的 16 位半精度 浮点表示。
¥The nearest 16-bit half precision float representation of doubleFloat
.
描述
¥Description
Math.f16round
是 Math.fround()
的 16 位对应项。它旨在在与 float16 数字交互时平滑一些粗糙的边缘,例如从 Float16Array
读取时。在内部,JavaScript 继续将数字视为 64 位浮点数,它只对尾数的第 10 位执行 "四舍五入到偶数",并将所有后续尾数位设置为 0
。如果数字超出 16 位浮点数的范围,则返回 Infinity
或 -Infinity
。
¥Math.f16round
is the 16-bit counterpart of Math.fround()
. It is intended to smooth some rough edges when interacting with float16 numbers, such as when reading from a Float16Array
. Internally, JavaScript continues to treat the number as a 64-bit float, it just performs a "round to even" on the 10th bit of the mantissa, and sets all following mantissa bits to 0
. If the number is outside the range of a 16-bit float, Infinity
or -Infinity
is returned.
因为 f16round()
是 Math
的静态方法,所以你始终将其用作 Math.f16round()
,而不是用作你创建的 Math
对象的方法(Math
不是构造函数)。
¥Because f16round()
is a static method of Math
, you always use it as Math.f16round()
, rather than as a method of a Math
object you created (Math
is not a constructor).
示例
使用 Math.f16round()
¥Using Math.f16round()
数字 1.5 可以在二进制数字系统中精确表示,并且在 16 位和 64 位中相同:
¥The number 1.5 can be precisely represented in the binary numeral system, and is identical in 16-bit and 64-bit:
Math.f16round(1.5); // 1.5
Math.f16round(1.5) === 1.5; // true
但是,数字 1.337 无法在二进制数字系统中精确表示,因此它在 16 位和 64 位中有所不同:
¥However, the number 1.337 cannot be precisely represented in the binary numeral system, so it differs in 16-bit and 64-bit:
Math.f16round(1.337); // 1.3369140625
Math.f16round(1.337) === 1.337; // false
100000 对于 16 位浮点数来说太大,因此返回 Infinity
:
¥100000 is too big for a 16-bit float, so Infinity
is returned:
Math.f16round(100000); // Infinity
规范
Specification |
---|
Float16Array # sec-math.f16round |
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