.. _error-code-evrf019:

.. meta::
   :description: AWS Neuron SDK Graph Compiler error code documentation for error EVRF019.

NCC_EVRF019
===========

**Error message**: The compiler encountered a reduce-window operation with more or less than 2 operands. Support for reduce_window is available for exactly one input tensor and one initial value for reduction.

Erroneous code example:

.. code-block:: python

    # reduce-window operation with more or less than 2 operands is not supported
    # 4 operands are being provided instead of 2
    lax.reduce_window(
        (x, x),               # ERROR: a tuple of two input tensors
        (-jnp.inf, jnp.inf),  # ERROR: a tuple of two initial values
        lambda a, b: (jnp.maximum(a[0], b[0]), jnp.minimum(a[1], b[1])),
        window_dimensions=(1, 2, 2, 1),
        window_strides=(1, 2, 2, 1),
        padding='VALID'
    )


If possible, split multi-operand reduce_window with multiple single-operand reduce_window operations.

.. code-block:: python

    # For max pooling
    # 2 operands are correctly being provided
    max_pool = lax.reduce_window(
        x,         # FIXED: a single input tensor
        -jnp.inf,  # FIXED: a single initial value
        lax.max,
        window_dimensions=(1, 2, 2, 1),
        window_strides=(1, 2, 2, 1),
        padding='VALID'
    )
    
    # For min pooling
    # 2 operands are correctly being provided
    min_pool = lax.reduce_window(
        x,        # FIXED: a single input tensor
        jnp.inf,  # FIXED: a single initial value
        lax.min,
        window_dimensions=(1, 2, 2, 1),
        window_strides=(1, 2, 2, 1),
        padding='VALID'
    )