> ## 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.

# Transfer Function Block

The **Transfer Function** block works very similarly to multiple mini ramps put together. This block gives you more control over the changes throughout the domain.

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Instead of taking in minimum and maximum input and output values like the **Ramp**block, the **Transfer Function** requires lists of values as it uses piecewise interpolation to compute the output field value of a function approximated by a set of field data points.

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  <img src="https://files.learn.ntop.com/lessons/transfer-function-block/220_9_2-tf.jpg" />
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* **Value**: The field driving the Transfer Function, a reference for the input domain.
* **Input**: Pre-populated as a Scalar List for a user-defined set of values.

You can use the **Sequence from Bounds**, **Sequence**, or **Random Sequence** blocks for incremented or random set of values. You can find these in the *Math*tab of the Ribbon under *Utilities*. To learn more about using these sequence blocks, visit our [230: Intro to Automation](https://learn.ntop.com/courses/230-intro-to-automation/) course.

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* **Output**: A Scalar Field List of output values. The length of this list should match the length of the **Input**list.

<Note>
  **Note**: When defining the Input and Output values, ***make sure to******include units**\*\*.*
</Note>

* **Extrapolation**: How the output values extend beyond the specified input domain. See the image below for a comparison of the two options.
  * Clamped: Bounding output values remain constant beyond the specified domain
  * Linear: Linear extrapolation of output values beyond the specified domain

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  <img src="https://files.learn.ntop.com/lessons/transfer-function-block/220_9_4-cropextra-1.jpg" />
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Example of the two extrapolation options

## Example Application

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  <img src="https://files.learn.ntop.com/lessons/transfer-function-block/220_9_5-TFExample.jpg" />
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Advanced manipulation of beam thickness and density of a Voronoi lattice using a Transfer Function