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nan

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In computing, NaN, which stands for Not a Number, is a value or symbol that is usually produced as a result of an operation on invalid input operands. For example, most floating-point units are unable to explicitly calculate the square root of negative numbers, and will instead indicate that the operation was invalid and return a NaN result. | In computing, NaN, which stands for Not a Number, is a value or symbol that is usually produced as a result of an operation on invalid input operands. For example, most floating-point units are unable to explicitly calculate the square root of negative numbers, and will instead indicate that the operation was invalid and return a NaN result. | ||

- | An invalid operation is not the same as an arithmetic overflow (which returns a positive or negative infinity). Arithmetic operations involving NaN always produce NaN, allowing the value to propagate through a calculation so that errors can be detected at the end without extensive testing during intermediate stages. | + | An invalid operation is not the same as an arithmetic overflow (which returns a positive or negative infinity). Arithmetic operations involving NaN always produce NaN, allowing the value to propagate through a calculation so that errors can be detected at the end without extensive testing during intermediate stages. A NaN does not compare equal to any number or NaN. |

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- | A NaN does not compare equal to any number or NaN. You can therefore test whether a variable has a NaN value by comparing it to itself: if ''. | + | |

==== How does a NaN appear? ==== | ==== How does a NaN appear? ==== | ||

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===== NaN in Expressions ===== | ===== NaN in Expressions ===== | ||

You can use predefined constants '' | You can use predefined constants '' | ||

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+ | The '' | ||

=== Example === | === Example === | ||

* If you set a [[set_column_formula|Column Formula]] '' | * If you set a [[set_column_formula|Column Formula]] '' |

nan.1288541213.txt.gz · Last modified: Sun Nov 8 12:20:32 2015 (external edit)

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