math.scalbln Method (Single, Int64)

mathscalbln Method (Single, Int64)

Scales the specified floating-point number by 2^exponent.

Namespace: C
Assembly: C.math (in C.math.dll) Version: 1.0.0.0 (1.0.0.0)

Syntax

public static float scalbln(
	float number,
	long exponent
)

Public Shared Function scalbln ( 
	number As Single,
	exponent As Long
) As Single

public:
static float scalbln(
	float number, 
	long long exponent
)

static member scalbln : 
        number : float32 * 
        exponent : int64 -> float32

Parameters

number: Type: SystemSingle
A floating-point number.
exponent: Type: SystemInt64
The exponent of the power of two.

Return Value

Type: Single
The value number * 2^exponent.

Remarks

Special values are treated as follows.

If number is ±0, it is returned.
If number is infinite, it is returned.
If exponent is 0, number is returned.
If number is NaN, NaN is returned.

The function scalbln(Single, Int64) is equivalent to ldexp(Single, Int32).

See scalbln in the C standard documentation.

Examples

C++

Copy

Assert.IsTrue(math.scalbln(0.8F, 4L) == 12.8F);
Assert.IsTrue(math.scalbln(-0.854375F, 5L) == -27.34F);
Assert.IsTrue(math.scalbln(1F, 0L) == 1F);

Assert.IsTrue(math.scalbln(math.FLT_MIN / 2F, 0L) == math.FLT_MIN / 2F);
Assert.IsTrue(math.scalbln(math.FLT_MIN / 2F, 1L) == math.FLT_MIN);
Assert.IsTrue(math.scalbln(math.FLT_MIN * 1.5F, -math.FLT_MANT_BITS) == 2F * math.FLT_DENORM_MIN);
Assert.IsTrue(math.scalbln(math.FLT_MIN * 1.5F, -math.FLT_MANT_BITS - 1) == math.FLT_DENORM_MIN);
Assert.IsTrue(math.scalbln(math.FLT_MIN * 1.25F, -math.FLT_MANT_BITS) == math.FLT_DENORM_MIN);
Assert.IsTrue(math.scalbln(math.FLT_MIN * 1.25F, -math.FLT_MANT_BITS - 1) == math.FLT_DENORM_MIN);

Assert.IsTrue(math.scalbln(1F, System.Int64.MaxValue) == System.Single.PositiveInfinity);
Assert.IsTrue(math.scalbln(1F, System.Int64.MinValue) == 0F);
Assert.IsTrue(math.scalbln(-1F, System.Int64.MaxValue) == System.Single.NegativeInfinity);
Assert.IsTrue(math.scalbln(-1F, System.Int64.MinValue) == -0F);

Assert.IsTrue(math.scalbln(0.8F, 4L) = 12.8F);
Assert.IsTrue(math.scalbln(-0.854375F, 5L) = -27.34F);
Assert.IsTrue(math.scalbln(1F, 0L) = 1F);

Assert.IsTrue(math.scalbln(math.FLT_MIN / 2F, 0L) = math.FLT_MIN / 2F);
Assert.IsTrue(math.scalbln(math.FLT_MIN / 2F, 1L) = math.FLT_MIN);
Assert.IsTrue(math.scalbln(math.FLT_MIN * 1.5F, -math.FLT_MANT_BITS) = 2F * math.FLT_DENORM_MIN);
Assert.IsTrue(math.scalbln(math.FLT_MIN * 1.5F, -math.FLT_MANT_BITS - 1) = math.FLT_DENORM_MIN);
Assert.IsTrue(math.scalbln(math.FLT_MIN * 1.25F, -math.FLT_MANT_BITS) = math.FLT_DENORM_MIN);
Assert.IsTrue(math.scalbln(math.FLT_MIN * 1.25F, -math.FLT_MANT_BITS - 1) = math.FLT_DENORM_MIN);

Assert.IsTrue(math.scalbln(1F, System.Int64.MaxValue) = System.Single.PositiveInfinity);
Assert.IsTrue(math.scalbln(1F, System.Int64.MinValue) = 0F);
Assert.IsTrue(math.scalbln(-1F, System.Int64.MaxValue) = System.Single.NegativeInfinity);
Assert.IsTrue(math.scalbln(-1F, System.Int64.MinValue) = -0F);

Reference

math Class

scalbln Overload

C Namespace