def load_grid_small():
    """Load a small parameter grid for GenSVM

    This function loads a default parameter grid to use for the #' GenSVM 
    gridsearch. It contains all possible combinations of the following #' 
    parameter sets::

        pg = {
            'p': [1.0, 1.5, 2.0],
            'lmd': [1e-8, 1e-6, 1e-4, 1e-2, 1],
            'kappa': [-0.9, 0.5, 5.0],
            'weights': ['unit', 'group'],
        }

    Returns
    -------

    pg : dict
        Mapping from parameters to lists of values for those parameters. To be 
        used as input for the :class:`.GenSVMGridSearchCV` class.
    """
    pg = {'p': [1.0, 1.5, 2.0], 'lmd': [1e-08, 1e-06, 0.0001, 0.01, 1],
        'kappa': [-0.9, 0.5, 5.0], 'weights': ['unit', 'group']}
    return pg
