keras-team/keras · error · ValueError

Both input arrays must be (arrays of) 2 or 3-dimensional vec

Error message

Both input arrays must be (arrays of) 2 or 3-dimensional vectors, but they are {x1_dim} and {x2_dim} dimensional instead.

What it means

Error "Both input arrays must be (arrays of) 2 or 3-dimensional vectors, but they are {x1_dim} and {x2_dim} dimensional instead." thrown in keras-team/keras.

Source

Thrown at keras/src/backend/numpy/numpy.py:565

def cross(x1, x2, axisa=-1, axisb=-1, axisc=-1, axis=None):
    axis = standardize_axis_for_numpy(axis)
    x1 = convert_to_tensor(x1)
    x2 = convert_to_tensor(x2)
    dtype = dtypes.result_type(x1.dtype, x2.dtype)
    x1 = x1.astype(dtype)
    x2 = x2.astype(dtype)

    if axis is not None:
        axisa = axis
        axisb = axis
        axisc = axis
    x1 = np.moveaxis(x1, axisa, -1)
    x2 = np.moveaxis(x2, axisb, -1)

    x1_dim = x1.shape[-1]
    x2_dim = x2.shape[-1]
    if x1_dim not in (2, 3) or x2_dim not in (2, 3):
        raise ValueError(
            "Both input arrays must be (arrays of) 2 or 3-dimensional "
            f"vectors, but they are {x1_dim} and {x2_dim} dimensional "
            "instead."
        )

    # NumPy>=2.5 removed support for 2-dimensional vectors in `np.cross`
    # (https://numpy.org/doc/stable/release/2.5.0-notes.html), so pad them
    # to 3 dimensions ourselves (with an implicit zero z-component) before
    # delegating the cross product of the resulting 3-dimensional vectors
    # to `np.cross`.
    def _pad_2d_vector_to_3d(x):
        if x.shape[-1] == 2:
            return np.pad(x, [(0, 0)] * (x.ndim - 1) + [(0, 1)])
        return x

    x1 = _pad_2d_vector_to_3d(x1)
    x2 = _pad_2d_vector_to_3d(x2)

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/backend/numpy/numpy.py:565 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of keras-team/keras@7a34a03db6 (2026-08-25). Data as JSON: /api/errors/60f34fd5ad1d918a. Report an issue: GitHub.