Function batchConcat

tfjs-data/src/dataset.ts:691–705

* Assembles a list of same-shaped numbers, number arrays, or Tensors * into a single new Tensor where axis 0 is the batch dimension.

(arrays: T[])

 * into a single new Tensor where axis 0 is the batch dimension.
 */
function batchConcat<T extends(TensorLike | tf.Tensor)>(arrays: T[]):
    tf.Tensor {
  if (arrays.length === 0) {
    // We can't return an empty Tensor because we don't know the element shape.
    throw new Error('Can\'t make a batch of zero elements.');
  }

  if (arrays[0] instanceof tf.Tensor) {
    // Input is an array of Tensors
    return tf.stack(arrays as tf.Tensor[]);
  } else {
    // Input is a possibly-nested array of numbers.
    return tf.tensor(arrays as TensorLike);
  }
}