Ejemplo n.º 1
0
        def calc_model(h_sd, alphaG):
            rh2_model = s14.calc_rh2(h_sd, alphaG, Z, phi_g=phi_g,
                                     return_fractions=False,
                                     radiation_type=radiation_type,
                                     )

            return rh2_model
Ejemplo n.º 2
0
 def odr_func(Z, h_sd):
     return s14.calc_rh2(
         h_sd,
         alphaG,
         Z,
         phi_g=phi_g,
         return_fractions=False,
         radiation_type=radiation_type,
     )
Ejemplo n.º 3
0
        def calc_residual(params, h_sd, rh2):
            alphaG = params['alphaG'].value
            phi_g = params['phi_g'].value
            Z = params['Z'].value

            rh2_model = s14.calc_rh2(h_sd, alphaG, Z, phi_g=phi_g,
                                     return_fractions=False)

            residual = rh2 - rh2_model

            return residual
Ejemplo n.º 4
0
 def odr_func(alphaG, h_sd,):
     if 0:
         plt.scatter(h_sd, rh2)
         plt.yscale('log')
         plt.ylim([1e-3, 1e2])
         plt.annotate(alphaG, xy=(0.8, 0.1), xycoords='axes fraction')
         plt.show()
     rh2_model = s14.calc_rh2(h_sd, alphaG, Z, phi_g=phi_g,
                              return_fractions=False,
                              radiation_type=radiation_type,
                              )
     return rh2_model
Ejemplo n.º 5
0
        def calc_residual(params, h_sd, rh2, rh2_error=None):
            alphaG = params['alphaG'].value

            rh2_model = s14.calc_rh2(h_sd, alphaG, Z, phi_g=phi_g,
                                     return_fractions=False,
                                     radiation_type=radiation_type,
                                     )
            if rh2_error is not None:
                residual = (rh2 - rh2_model) / rh2_error
            else:
                residual = rh2 - rh2_model

            return residual
Ejemplo n.º 6
0
        def calc_residual(params, h_sd, rh2):
            alphaG = params['alphaG'].value
            phi_g = params['phi_g'].value
            Z = params['Z'].value

            rh2_model = s14.calc_rh2(h_sd,
                                     alphaG,
                                     Z,
                                     phi_g=phi_g,
                                     return_fractions=False)

            residual = rh2 - rh2_model

            return residual
Ejemplo n.º 7
0
        def calc_model(alphaG):
            if 0:
                plt.scatter(h_sd, rh2)
                #plt.yscale('log')
                #plt.ylim([1e-3, 1e2])
                plt.annotate(alphaG, xy=(0.8, 0.1), xycoords='axes fraction')
                plt.show()

            rh2_model = s14.calc_rh2(h_sd, alphaG, Z, phi_g=phi_g,
                                     return_fractions=False,
                                     radiation_type=radiation_type,
                                     )

            #mask = rh2_model < 0
            #print np.sum(rh2_model[~mask] < 0)
            mask = np.zeros(np.size(rh2), dtype=bool)

            chisq = np.nansum((rh2[~mask] - rh2_model[~mask])**2 / \
                    rh2_error[~mask]**2)

            return chisq
Ejemplo n.º 8
0
 def odr_func(Z, h_sd):
     return s14.calc_rh2(h_sd, alphaG, Z, phi_g=phi_g,
                              return_fractions=False,
                              radiation_type=radiation_type,
                              )
Ejemplo n.º 9
0
def fit_sternberg(h_sd, rh2, guesses=[10,], rh2_error=None,
        h_sd_error=None, radiation_type='beamed', phi_g=2.0, Z=1.0,):

    '''
    Parameters
    ----------
    h_sd : array-like
        Hydrogen surface density in units of solar mass per parsec**2
    rh2 : array-like
        Ratio between molecular and atomic hydrogen masses.
    guesses : None, scalar, or M-length sequence.
        Initial guess for the parameters. See scipy.optimize.curve_fit.
    rh2_error : bool
        Error in rh2 parameter. Calculates a more accurate chi^2 statistic

    Returns
    -------
    rh2_fit_params : array-like, optional
        Model parameter fits.


    Residual bootstrapping:
    http://stats.stackexchange.com/questions/67519/bootstrapping-residuals-am-i-doing-it-right


    '''

    import sys
    sys.path.insert(0, '/usr/users/ezbc/.local/lib64/python2.7/site-packages/')
    from scipy.optimize import curve_fit, minimize
    from scipy import stats
    import scipy
    #from lmfit import minimize, Parameters, report_fit, Minimizer
    #import lmfit
    from myscience import sternberg14 as s14
    import mystats
    import scipy.odr as odr

    if any(np.isnan(h_sd)):
        raise ValueError('HSD should not have nans')

    mask = (rh2 < 0.0) | (np.isnan(h_sd))
    mask = np.isnan(h_sd)
    h_sd = h_sd[~mask]
    rh2 = rh2[~mask]
    rh2_error = rh2_error[~mask]

    if 0:
        def calc_residual(params, h_sd, rh2, rh2_error=None):
            alphaG = params['alphaG'].value

            rh2_model = s14.calc_rh2(h_sd, alphaG, Z, phi_g=phi_g,
                                     return_fractions=False,
                                     radiation_type=radiation_type,
                                     )
            if rh2_error is not None:
                residual = (rh2 - rh2_model) / rh2_error
            else:
                residual = rh2 - rh2_model

            return residual

        # Set parameter limits and initial guesses
        params = Parameters()
        params.add('alphaG',
                   value=guesses[0],
                   min=0.01,
                   max=1000,
                   vary=True)

        # Perform the fit!
        result = minimize(calc_residual,
                          params,
                          args=(h_sd, rh2, rh2_error),
                          method='leastsq',
                          #method='anneal',
                          is_weighted=True,
                          )

        # best-fit parameter
        alphaG = params['alphaG'].value
    elif 0:
        def calc_model(h_sd, alphaG):
            rh2_model = s14.calc_rh2(h_sd, alphaG, Z, phi_g=phi_g,
                                     return_fractions=False,
                                     radiation_type=radiation_type,
                                     )

            return rh2_model

        popt, pcov = curve_fit(calc_model,
                               h_sd,
                               rh2,
                               p0=guesses,
                               sigma=rh2_error,
                               method='lm',
                               )

        alphaG = popt[0]
    elif 1:
        def calc_model(alphaG):
            if 0:
                plt.scatter(h_sd, rh2)
                #plt.yscale('log')
                #plt.ylim([1e-3, 1e2])
                plt.annotate(alphaG, xy=(0.8, 0.1), xycoords='axes fraction')
                plt.show()

            rh2_model = s14.calc_rh2(h_sd, alphaG, Z, phi_g=phi_g,
                                     return_fractions=False,
                                     radiation_type=radiation_type,
                                     )

            #mask = rh2_model < 0
            #print np.sum(rh2_model[~mask] < 0)
            mask = np.zeros(np.size(rh2), dtype=bool)

            chisq = np.nansum((rh2[~mask] - rh2_model[~mask])**2 / \
                    rh2_error[~mask]**2)

            return chisq

        res = minimize(calc_model,
                       guesses[0],
                       #method='powell',
                       #method='nelder-mead',
                       method='L-BFGS-B',
                       bounds=[[0, None],],
                       options={'disp':False},
                       )

        alphaG = res.x[0]
    else:
        def odr_func(alphaG, h_sd,):
            if 0:
                plt.scatter(h_sd, rh2)
                plt.yscale('log')
                plt.ylim([1e-3, 1e2])
                plt.annotate(alphaG, xy=(0.8, 0.1), xycoords='axes fraction')
                plt.show()
            rh2_model = s14.calc_rh2(h_sd, alphaG, Z, phi_g=phi_g,
                                     return_fractions=False,
                                     radiation_type=radiation_type,
                                     )
            return rh2_model

        model = odr.Model(odr_func)
        data = odr.RealData(h_sd, rh2, sy=rh2_error)
        odr_instance = odr.ODR(data, model, beta0=guesses)
        output = odr_instance.run()
        alphaG = output.beta[0]

    # calculate model for observed H
    rh2_model = s14.calc_rh2(h_sd, alphaG, Z, phi_g=phi_g,
                             return_fractions=False,
                             radiation_type=radiation_type,
                             )

    # calculate model for resampled H
    h_sd_resampled = np.logspace(-3, 3, 1000)
    rh2_resampled = s14.calc_rh2(h_sd_resampled, alphaG, Z, phi_g=phi_g,
                             return_fractions=False,
                             radiation_type=radiation_type,
                             )

    return alphaG, rh2_model, rh2_resampled, h_sd_resampled