# $sin
<a name="sin"></a>

New from version 8.0.1.

The `$sin` operator in Amazon DocumentDB returns the sine of a value that is measured in radians. Use it in the aggregation pipeline to perform trigonometric calculations on numeric fields.

**Parameters**
+ `expression`: An expression that resolves to a number in radians.

## Example (MongoDB Shell)
<a name="sin-examples"></a>

The following example shows how to use the `$sin` operator to calculate the sine of angle values in radians.

**Create sample documents**

```
db.angles.insertMany([
  { "_id": 1, "angle": 0 },
  { "_id": 2, "angle": 0.5235987755982988 },
  { "_id": 3, "angle": 1.5707963267948966 }
]);
```

**Query example**

```
db.angles.aggregate([
  { $project: {
    "sine": { $sin: "$angle" }
  }}
]);
```

**Output**

```
[
  { "_id": 1, "sine": 0 },
  { "_id": 2, "sine": 0.49999999999999994 },
  { "_id": 3, "sine": 1 }
]
```

## Code examples
<a name="sin-code"></a>

To view a code example for using the `$sin` operator, choose the tab for the language that you want to use:

------
#### [ Node.js ]

```
const { MongoClient } = require('mongodb');

async function main() {
  const client = await MongoClient.connect('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false');
  const db = client.db('test');
  const collection = db.collection('angles');

  const result = await collection.aggregate([
    { $project: {
      "sine": { $sin: "$angle" }
    }}
  ]).toArray();

  console.log(result);
  await client.close();
}

main();
```

------
#### [ Python ]

```
from pymongo import MongoClient

def main():
    client = MongoClient('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false')
    db = client['test']
    collection = db['angles']

    result = list(collection.aggregate([
        { '$project': {
            'sine': { '$sin': '$angle' }
        }}
    ]))

    print(result)
    client.close()

if __name__ == "__main__":
    main()
```

------