Characteristics of floating-point types
This header describes the characteristics of floating types for the specific system and compiler implemetation used.
A floating-point number is composed of four elements:
- a sign: either negative or non-negative
- a base (or radix): which expresses the amount of quantities that can be represented with a single digit (2 for binary, 10 for decimal, 16 for hexadecimal, and so on...)
- a significand (or mantissa): which is a series of digits of the abovementioned base. The number of digits in this series is what is known as precision.
- an exponent (also knon as characteristic, or scale): which represents the offset of the significand, which affects the value in the following way:
value of floating-point = significand x baseexponent, with its corresponding sign.
The following panel shows the name of the different values defined in this header and their minimal magnitudes (positive numbers may be greater in value, and negative number may be less in value). Any particular implementation may have characteristics with greater magnitudes than those shown here:
*Except for FLT_RADIX, names beginning with FLT apply to the float type, those with DBL to double and those with LDBL to long double.
|FLT_RADIX||2||RADIX||Base for all floating-point types (float, double and long double).|
| ||MANTissa DIGits||Precission of significand, i.e. the number of digits that conform the significand.|
|DIGits||Number of decimal digits that can be rounded into a floating-point and back without change in the number of decimal digits.|
| ||MINimum EXPonent||Minimum negative integer value for the exponent that generates a normalized floating-point number.|
|MINimum base-10 EXPonent||Minimum negative integer value for the exponent of a base-10 expression that would generate a normalized floating-point number.|
| ||MAXimum EXPonent||Maximum integer value for the exponent that generates a normalized floating-point number.|
|MAXimum base-10 EXPonent||Maximum integer value for the exponent of a base-10 expression that would generate a normalized floating-point number.|
|MAXimum||Maximum finite representable floating-point number.|
|EPSILON||Difference between 1 and the least value greater than 1 that is representable.|
|MINimum||Minimum representable floating-point number.|