> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ntop.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Curve Integral

<CardGroup cols={2}>
  <Card title="Curve (old), Scalar Field, Scalar" href="#curve-old-scalar-field-scalar" />

  <Card title="Curve, Scalar Field, Scalar, 5.20.0" href="#curve-scalar-field-scalar-5200" />
</CardGroup>

***

## About this Block

**What it does:** The **Curve Integral** block integrates the values of a Scalar Field along a curve.

**Common uses:**

* Calculate length

## Example File

![Curve Integral](https://storage.googleapis.com/files-learn/static/ExtendedBlockDocs/curveintegral.jpg)

***

<h2 id="curve-old-scalar-field-scalar">
  Curve (old), Scalar Field, Scalar
</h2>

Integrate a Scalar Field along a curve.

### Inputs

| Name           | Type                                                               | Description                                                 |
| -------------- | ------------------------------------------------------------------ | ----------------------------------------------------------- |
| Curve          | [Curve (old)](../../../../block-documentation/types/curve-old)     | The curve to integrate along.                               |
| Integrand      | [Scalar Field](../../../../block-documentation/types/scalar-field) | The function that will be integrated.                       |
| Relative error | [Scalar](../../../../block-documentation/types/scalar)             | The relative error used to determine algorithm convergence. |

### Outputs

| Type                                                   |
| ------------------------------------------------------ |
| [Scalar](../../../../block-documentation/types/scalar) |

***

<h2 id="curve-scalar-field-scalar-5200">
  Curve, Scalar Field, Scalar, 5.20.0
</h2>

Integrate a Scalar Field along a curve.

### Inputs

| Name           | Type                                                               | Description                                                 |
| -------------- | ------------------------------------------------------------------ | ----------------------------------------------------------- |
| Curve          | [Curve](../../../../block-documentation/types/curve)               | The curve to integrate along.                               |
| Integrand      | [Scalar Field](../../../../block-documentation/types/scalar-field) | The function that will be integrated.                       |
| Relative error | [Scalar](../../../../block-documentation/types/scalar)             | The relative error used to determine algorithm convergence. |

### Outputs

| Type                                                   |
| ------------------------------------------------------ |
| [Scalar](../../../../block-documentation/types/scalar) |