def unsqueeze(data, axis, oldshape):
    """
    Unsqueeze a collapsed array

    >>> from numpy import mean
    >>> from numpy.random import standard_normal
    >>> x = standard_normal((3,4,5))
    >>> m = mean(x, axis=1)
    >>> m.shape
    (3, 5)
    >>> m = unsqueeze(m, 1, x.shape)
    >>> m.shape
    (3, 1, 5)
    >>>
    """
    newshape = list(oldshape)
    newshape[axis] = 1
    return data.reshape(newshape)
