# isnan

Check for Not a Number entries.

## 📝 Syntaxe

* tf = isnan(M)

## 📥 Argument d'entrée

* M - a variable

## 📤 Argument de sortie

* tf - logical: result of 'isnan'.

## 📄 Description

isnan returns a logical array which is true where elements of M are "Not a Number" values.

## 💡 Exemple

```matlab
isnan(pi)
isnan(NaN)
isnan(int32(3))
X = sparse([1 2 NaN 3 0 NaN 0 4]);
R = isnan(X)
```

## 🔗 Voir aussi

[isinf](https://nelson-9.gitbook.io/nelson/markdown/fr/elementary_functions/isinf).

## 🕔 Historique

| Version | 📄 Description   |
| ------- | ---------------- |
| 1.0.0   | version initiale |
