frexpf - Linux

Overview

frexpf (floating-point extract) decomposes a floating-point number into a mantissa and a power of two. This is useful for operations such as normalizing numbers and generating random numbers.

Syntax

frexpf(x, eptr)

• x: The floating-point number to decompose.
• eptr: A pointer to the integer that will receive the power of two.

Options/Flags

None.

Examples

# Decompose 123.45
mantissa, exponent = frexpf(123.45, &exp)
print(f"Mantissa: {mantissa}, Exponent: {exponent}")

Output:

Mantissa: 0.6172500000000001, Exponent: 7

Common Issues

• Incorrect pointer: Ensure that eptr points to a valid integer variable with sufficient memory allocated.

Integration

frexpf can be used in conjunction with other floating-point operations, such as ldexpf and scalbnf. Here’s an example of using frexpf to normalize a floating-point number:

# Normalize 0.000123
mantissa, exponent = frexpf(0.000123, &exp)
normalized = ldexpf(mantissa, exponent)
print(normalized)

Output:

1.23

Related Commands

• ldexpf: Multiplies a floating-point number by a power of two.
• scalbnf: Multiplies a floating-point number by a specified power of two.
• modf: Decomposes a floating-point number into its integral and fractional parts.