# Massage data about "nan"

**URL:** <https://forum.opencyphal.org/t/massage-data-about-nan/286>\
**Category:** Libcanard\
**Created:** [December 12, 2018, 8:11am UTC](https://forum.opencyphal.org/t/massage-data-about-nan/286 "2018-12-12T08:11:14Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![skyyuzhang](https://forum.opencyphal.org/user_avatar/forum.opencyphal.org/skyyuzhang/32/65_2.png) [@skyyuzhang](https://forum.opencyphal.org/u/skyyuzhang)\
**Post date:** [December 12, 2018, 8:11am UTC](https://forum.opencyphal.org/t/massage-data-about-nan/286/1 "2018-12-12T08:11:14Z")

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the follow picture.you can see “temperatue: nan” so what is “nan”? if I want to send value nan How? thank you

 ![%E5%8F%82%E8%80%83](https://forum.opencyphal.org/uploads/default/original/1X/1a2f031acfc950b2652e5d6995ca808c9f66983c.jpeg)

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**Author:** ![pavel.kirienko](https://forum.opencyphal.org/user_avatar/forum.opencyphal.org/pavel.kirienko/32/9_2.png) [@pavel.kirienko](https://forum.opencyphal.org/u/pavel.kirienko)\
**Post date:** [December 12, 2018, 8:29am UTC](https://forum.opencyphal.org/t/massage-data-about-nan/286/2 "2018-12-12T08:29:29Z")

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> **[NaN](https://en.wikipedia.org/wiki/NaN)**
>
> In computing, NaN, standing for not a number, is a numeric data type value representing an undefined or unrepresentable value, especially in floating-point calculations. Systematic use of NaNs was introduced by the IEEE 754 floating-point standard in 1985, along with the representation of other non-finite quantities like infinities.
> Two separate kinds of NaNs are provided, termed quiet NaNs and signaling NaNs. Quiet NaNs are used to propagate errors resulting from invalid operations or values, ...

[https://en.cppreference.com/w/c/numeric/math/nan](https://en.cppreference.com/w/c/numeric/math/nan)