The IEEE Standard 754 defines a class of numbers known as NaN, or Not a Number. This value is used by the IRIS processing software to indicate missing data.

A floating-point value that is said to be "not a number" and contains an indeterminate quantity.

A special bit pattern produced when a floating-point operation cannot produce a meaningful result (for example, 0/0 produces a NaN). NaNs propagate through arithmetic operations.

Not-a-Number, the condition that results from a floating-point operation that has no mathematical meaning, such as infinity divided by infinity. The ON statement can be used to trap operations that result in NaN.

floating-point value that is represented by a sign bit fraction with at least one bit set to 1, and an exponent with all bits set to 1. See also signaling NaN (SNaN), quiet NaN (QNaN).

See not-a-number.

Acronym for “not a number.” Math coprocessors generate NANs when the result of an operation cannot be represented in IEEE format. For example, if two numbers being multiplied have a product larger than the maximum value permitted, the coprocessor returns a NAN instead of the product.

Not a Number, a computing expression for bit strings in numeric fields which do not interpret as numbers. It can be encountered by invalid calculations or used as a flag to prevent use of invalid values where no proper value exists.

number value representing Not-a-Number. See NaN.

This is a special value of the double and float data types that represents an undefined result of a mathematical operation, such as zero divided by zero.

Missing data or values that are indeterminate are assigned the place holder "NaN", standing for "Not a Number", according to IEEE-754. See http://en.wikipedia.org/wiki/NAN

Not-a-Number. The condition that results from a floating-point operation that has no mathematical meaning; for example, zero divided by zero.