Exemple #1
0
def find_max_llh_bfgs(fmap, template_maker, params, bfgs_settings, save_steps=False, normal_hierarchy=True):
    """
    Finds the template (and free systematic params) that maximize
    likelihood that the data came from the chosen template of true
    params, using the limited memory BFGS algorithm subject to bounds
    (l_bfgs_b).

    returns a dictionary of llh data and best fit params, in the format:
      {'llh': [...],
       'param1': [...],
       'param2': [...],
       ...}
    where 'param1', 'param2', ... are the free params varied by
    optimizer, and they hold a list of all the values tested in
    optimizer algorithm, unless save_steps is False, in which case
    they are one element in length-the best fit params and best fit llh.
    """

    # Get params dict which will be optimized (free_params) and which
    # won't be (fixed_params) but are still needed for get_template()
    fixed_params = get_fixed_params(select_hierarchy(params, normal_hierarchy))
    free_params = get_free_params(select_hierarchy(params, normal_hierarchy))

    init_vals = get_param_values(free_params)
    scales = get_param_scales(free_params)
    bounds = get_param_bounds(free_params)
    priors = get_param_priors(free_params)
    names = sorted(free_params.keys())

    # Scale init-vals and bounds to work with bfgs opt:
    init_vals = np.array(init_vals) * np.array(scales)
    bounds = [bounds[i] * scales[i] for i in range(len(bounds))]

    opt_steps_dict = {key: [] for key in names}
    opt_steps_dict["llh"] = []

    const_args = (names, scales, fmap, fixed_params, template_maker, opt_steps_dict, priors)

    physics.info("%d parameters to be optimized" % len(free_params))
    for name, init, (down, up), (prior, best) in zip(names, init_vals, bounds, priors):
        physics.info(
            ("%20s : init = %6.4f, bounds = [%6.4f,%6.4f], " "best = %6.4f, prior = " + ("%6.4f" if prior else "%s"))
            % (name, init, up, down, best, prior)
        )

    physics.debug("Optimizer settings:")
    for key, item in bfgs_settings.items():
        physics.debug("  %s -> `%s` = %.2e" % (item["desc"], key, item["value"]))

    best_fit_vals, llh, dict_flags = opt.fmin_l_bfgs_b(
        llh_bfgs, init_vals, args=const_args, approx_grad=True, iprint=0, bounds=bounds, **get_values(bfgs_settings)
    )

    best_fit_params = {name: value for name, value in zip(names, best_fit_vals)}

    # Report best fit
    physics.info("Found best LLH = %.2f in %d calls at:" % (llh, dict_flags["funcalls"]))
    for name, val in best_fit_params.items():
        physics.info("  %20s = %6.4f" % (name, val))

    # Report any warnings if there are
    lvl = logging.WARN if (dict_flags["warnflag"] != 0) else logging.DEBUG
    for name, val in dict_flags.items():
        physics.log(lvl, " %s : %s" % (name, val))

    if not save_steps:
        # Do not store the extra history of opt steps:
        for key in opt_steps_dict.keys():
            opt_steps_dict[key] = [opt_steps_dict[key][-1]]

    return opt_steps_dict
Exemple #2
0
def find_max_llh_bfgs(fmap, template_maker, params, bfgs_settings, save_steps=False,
                      normal_hierarchy=None, check_octant=False):
    """
    Finds the template (and free systematic params) that maximize
    likelihood that the data came from the chosen template of true
    params, using the limited memory BFGS algorithm subject to bounds
    (l_bfgs_b).

    returns a dictionary of llh data and best fit params, in the format:
      {'llh': [...],
       'param1': [...],
       'param2': [...],
       ...}
    where 'param1', 'param2', ... are the free params varied by
    optimizer, and they hold a list of all the values tested in
    optimizer algorithm, unless save_steps is False, in which case
    they are one element in length-the best fit params and best fit llh.
    """

    # Get params dict which will be optimized (free_params) and which
    # won't be (fixed_params) but are still needed for get_template()
    fixed_params = get_fixed_params(select_hierarchy(params,normal_hierarchy))
    free_params = get_free_params(select_hierarchy(params,normal_hierarchy))

    if len(free_params) == 0:
        logging.warn("NO FREE PARAMS, returning LLH")
        true_template = template_maker.get_template(get_values(fixed_params))
        channel = params['channel']['value']
        true_fmap = flatten_map(true_template,chan=channel)
        return {'llh': [-get_binwise_llh(fmap,true_fmap)]}

    init_vals = get_param_values(free_params)
    scales = get_param_scales(free_params)
    bounds = get_param_bounds(free_params)
    priors = get_param_priors(free_params)
    names  = sorted(free_params.keys())

    # Scale init-vals and bounds to work with bfgs opt:
    init_vals = np.array(init_vals)*np.array(scales)
    bounds = [bounds[i]*scales[i] for i in range(len(bounds))]

    opt_steps_dict = {key:[] for key in names}
    opt_steps_dict['llh'] = []

    const_args = (names,scales,fmap,fixed_params,template_maker,opt_steps_dict,priors)

    display_optimizer_settings(free_params, names, init_vals, bounds, priors,
                               bfgs_settings)

    best_fit_vals,llh,dict_flags = opt.fmin_l_bfgs_b(
        llh_bfgs, init_vals, args=const_args, approx_grad=True, iprint=0,
        bounds=bounds, **get_values(bfgs_settings))

    # If needed, run optimizer again, checking for second octant solution:
    if check_octant and ('theta23' in free_params.keys()):
        physics.info("Checking alternative octant solution")
        old_th23_val = free_params['theta23']['value']
        delta = np.pi - old_th23_val
        free_params['theta23']['value'] = np.pi + delta
        init_vals = get_param_values(free_params)

        const_args = (names,scales,fmap,fixed_params,template_maker,opt_steps_dict,priors)
        display_optimizer_settings(free_params, names, init_vals, bounds, priors,
                                   bfgs_settings)
        alt_fit_vals,alt_llh,alt_dict_flags = opt.fmin_l_bfgs_b(
            llh_bfgs, init_vals, args=const_args, approx_grad=True, iprint=0,
            bounds=bounds, **get_values(bfgs_settings))

        # Alternative octant solution is optimal:
        if alt_llh < llh:
            best_fit_vals = alt_fit_vals
            llh = alt_llh
            dict_flags = alt_dict_flags


    best_fit_params = { name: value for name, value in zip(names, best_fit_vals) }

    #Report best fit
    physics.info('Found best LLH = %.2f in %d calls at:'
        %(llh,dict_flags['funcalls']))
    for name, val in best_fit_params.items():
        physics.info('  %20s = %6.4f'%(name,val))

    #Report any warnings if there are
    lvl = logging.WARN if (dict_flags['warnflag'] != 0) else logging.DEBUG
    for name, val in dict_flags.items():
        physics.log(lvl," %s : %s"%(name,val))

    if not save_steps:
        # Do not store the extra history of opt steps:
        for key in opt_steps_dict.keys():
            opt_steps_dict[key] = [opt_steps_dict[key][-1]]

    return opt_steps_dict
Exemple #3
0
def find_max_llh_bfgs(fmap,
                      template_maker,
                      params,
                      bfgs_settings,
                      save_steps=False,
                      normal_hierarchy=None,
                      check_octant=False):
    """
    Finds the template (and free systematic params) that maximize
    likelihood that the data came from the chosen template of true
    params, using the limited memory BFGS algorithm subject to bounds
    (l_bfgs_b).

    returns a dictionary of llh data and best fit params, in the format:
      {'llh': [...],
       'param1': [...],
       'param2': [...],
       ...}
    where 'param1', 'param2', ... are the free params varied by
    optimizer, and they hold a list of all the values tested in
    optimizer algorithm, unless save_steps is False, in which case
    they are one element in length-the best fit params and best fit llh.
    """

    # Get params dict which will be optimized (free_params) and which
    # won't be (fixed_params) but are still needed for get_template()
    fixed_params = get_fixed_params(select_hierarchy(params, normal_hierarchy))
    free_params = get_free_params(select_hierarchy(params, normal_hierarchy))

    if len(free_params) == 0:
        logging.warn("NO FREE PARAMS, returning LLH")
        true_template = template_maker.get_template(get_values(fixed_params))
        channel = params['channel']['value']
        true_fmap = flatten_map(true_template, chan=channel)
        return {'llh': [-get_binwise_llh(fmap, true_fmap)]}

    init_vals = get_param_values(free_params)
    scales = get_param_scales(free_params)
    bounds = get_param_bounds(free_params)
    priors = get_param_priors(free_params)
    names = sorted(free_params.keys())

    # Scale init-vals and bounds to work with bfgs opt:
    init_vals = np.array(init_vals) * np.array(scales)
    bounds = [bounds[i] * scales[i] for i in range(len(bounds))]

    opt_steps_dict = {key: [] for key in names}
    opt_steps_dict['llh'] = []

    const_args = (names, scales, fmap, fixed_params, template_maker,
                  opt_steps_dict, priors)

    display_optimizer_settings(free_params, names, init_vals, bounds, priors,
                               bfgs_settings)

    best_fit_vals, llh, dict_flags = opt.fmin_l_bfgs_b(
        llh_bfgs,
        init_vals,
        args=const_args,
        approx_grad=True,
        iprint=0,
        bounds=bounds,
        **get_values(bfgs_settings))

    # If needed, run optimizer again, checking for second octant solution:
    if check_octant and ('theta23' in free_params.keys()):
        physics.info("Checking alternative octant solution")
        old_th23_val = free_params['theta23']['value']
        delta = np.pi - old_th23_val
        free_params['theta23']['value'] = np.pi + delta
        init_vals = get_param_values(free_params)

        const_args = (names, scales, fmap, fixed_params, template_maker,
                      opt_steps_dict, priors)
        display_optimizer_settings(free_params, names, init_vals, bounds,
                                   priors, bfgs_settings)
        alt_fit_vals, alt_llh, alt_dict_flags = opt.fmin_l_bfgs_b(
            llh_bfgs,
            init_vals,
            args=const_args,
            approx_grad=True,
            iprint=0,
            bounds=bounds,
            **get_values(bfgs_settings))

        # Alternative octant solution is optimal:
        if alt_llh < llh:
            best_fit_vals = alt_fit_vals
            llh = alt_llh
            dict_flags = alt_dict_flags

    best_fit_params = {
        name: value
        for name, value in zip(names, best_fit_vals)
    }

    #Report best fit
    physics.info('Found best LLH = %.2f in %d calls at:' %
                 (llh, dict_flags['funcalls']))
    for name, val in best_fit_params.items():
        physics.info('  %20s = %6.4f' % (name, val))

    #Report any warnings if there are
    lvl = logging.WARN if (dict_flags['warnflag'] != 0) else logging.DEBUG
    for name, val in dict_flags.items():
        physics.log(lvl, " %s : %s" % (name, val))

    if not save_steps:
        # Do not store the extra history of opt steps:
        for key in opt_steps_dict.keys():
            opt_steps_dict[key] = [opt_steps_dict[key][-1]]

    return opt_steps_dict