Fast Fourier Transform Node

The Fast Fourier Transform Node allows for transforming an array of data points from one domain (such as space or time) into a frequency representation using a fast Fourier transform algorithm.

Configuration

The Fast Fourier Transform Node takes three properties for its configuration.

Source Path

First, enter a payload path to an array of numbers on which to run the transformation. Each item in the array must be a real number, or the operation will fail.

Ideally, the length of the array should be a power of 2 — as in, the transformation should be applied to 2, 4, 8, 16, 32, 64, 128, etc. numbers. If the array length is not a power of 2, the node will add 0 values to the array until the next power of 2 length is reached.

Decimal Place Rounding

Next, you may optionally select a decimal place to round the output values to. Options range from No Rounding (full double-precision floating-point) to Ones (whole number). By default no rounding will occur, and the values will be double-precision floating-point numbers.

Result Path

Next, enter a payload path where the result of the transformation should be placed. The result will be an object containing the following properties:

• result: An array containing the calculated frequency domains.
• sampleCount: The length of the provided array of numbers.
• paddingCount: The amount of zeroes added to a non-power-of-two input array length.

Node Errors

There are a handful of common cases where the Fast Fourier Transform Node will throw an error:

• If the value at the source path is not an array.
• If the value is an array but the array is empty.
• If any item within the source array is not a number.