inverseTransform(out, data) {
        if (out === data)
            throw new Error('Input and output buffers must be different');

        this._transform4(out, data, -1 /* DONE */);
        for (let i = 0; i < out.length; ++i)
            out[i] /= this.size;
    }
Performs an inverse FFT transformation on the given `data` array, and stores the result in `out`.
The `out` array must be a different buffer than the `data` array. The `out` array will contain the
result of the transformation. The `data` array will not be modified.

@param {Float64Array} out The output buffer for the transformed data.
@param {Float64Array} data The input data to transform.
@throws {Error} If `out` and `data` refer to the same buffer.
@returns {void}