Extension:BCmath/Glossary

Glossary for BCmath is a list of core terms and concepts for bcmath, or arbitrary-precision arithmetic.

Terms and concepts

Arbitrary precision

When calculations are not limited by specific register sizes it is referred to as arbitrary precision.

Infinity (∞)

Infinite numbers are valid numbers that are represented with a particular Unicode symbol, the infinity (U+221E) codepoint.

An infinite number can have a sign, both a plus infinity (+∞) and a minus infinity (-∞).

NaN (nan)

Not-a-Number is the value of a calculation that has no valid representation as a number. It is called nan internally.

A NaN can have a payload that further clarify what it is or represents.

Operation: Numbers are combined they are said to be operands to an operation.; Operations and operands can have their own names, like addition has addend and augend.

Payload: When calculations generates a NaN, then additional information might be added to the payload.; Payloads might be inspected in the console, but will otherwise be silently forgotten.

Scale (scale)

The scale is how the number is shifted to process it efficiently. It is given as the argument scale to most operations.

The BCmath extension tries to estimate the scale factor if it is missing.