Exemple #1
0
dump("sinfo2.numpoints")

res = f.fit()
if res.succeeded: print("Fit succeeded")
if not res.succeeded: print("**** ERRRR, the fit failed folks")

report("res.format()")
report("res")

from sherpa.plot import DataPlot, ModelPlot
dplot = DataPlot()
dplot.prepare(f.data)
mplot = ModelPlot()
mplot.prepare(f.data, f.model)
dplot.plot()
mplot.overplot()

savefig("data_model_c0_c2.png")

dump("f.method.name")
original_method = f.method

from sherpa.optmethods import NelderMead
f.method = NelderMead()
resn = f.fit()
print("Change in statistic: {}".format(resn.dstatval))

fit2 = Fit(d, mdl, method=NelderMead())
fit2.fit()

mdl.c1.thaw()
Exemple #2
0
plt.plot(xmid, y2 / (xhi - xlo) / pha.exposure)

plt.xlabel('Energy (keV)')
plt.ylabel('Counts/sec/keV')

savefig('pha_eval_model_to_fit.png')

from sherpa.astro.plot import ModelHistogram
mplot = ModelHistogram()
mplot.prepare(pha, full)
mplot.plot()

savefig('pha_fullmodel_model.png')

from sherpa.fit import Fit
fit = Fit(pha, full)
res = fit.fit()

report('res.format()')

from sherpa.plot import ModelPlot

dplot.prepare(pha)
dplot.plot(xlog=True)

mplot2 = ModelPlot()
mplot2.prepare(pha, full)
mplot2.overplot()

savefig('pha_fullmodel_fit.png')
Exemple #3
0
def multifit(star_name, data_list, model_list, silent=False):
    """A function that will fit 2 models to 2 spectra simultaneously.
        This was created to fit the NaI doublets at ~3300 and ~5890 Angstroms.

    :param star_name: Name of the target star
    :type star_name: str
    :param data_list: List of spectrum data in the form [(wave, flux), (wave, flux),...]
    :type data_list: tuple
    :param model_list:  A list of unfit spectrum models
    :type model_list: list
    :param silent:  If true, no plots will generate, defaults to False
    :type silent: bool

    :return: models that are fit to the data
    :rtype: list

    """

    wave1, flux1 = data_list[0]
    wave2, flux2 = data_list[1]

    model1 = model_list[0]
    model2 = model_list[1]

    name_1 = star_name + " 1"
    name_2 = star_name + " 2"

    d1 = Data1D(name_1, wave1, flux1)
    d2 = Data1D(name_2, wave2, flux2)

    dall = DataSimulFit("combined", (d1, d2))
    mall = SimulFitModel("combined", (model1, model2))

    # # ==========================================
    # # Initial guesses

    # Dataset 1
    dplot1 = DataPlot()
    dplot1.prepare(d1)
    if silent is False:
        dplot1.plot()

    mplot1 = ModelPlot()
    mplot1.prepare(d1, model1)
    if silent is False:
        dplot1.plot()
        mplot1.overplot()
        plt.show()

        # Dataset 2
    dplot2 = DataPlot()
    dplot2.prepare(d2)
    if silent is False:
        dplot2.plot()

    mplot2 = ModelPlot()
    mplot2.prepare(d2, model2)
    if silent is False:
        dplot2.plot()
        mplot2.overplot()
        plt.show()

    # # =========================================
    # # Fitting happens here - don't break please
    stat = LeastSq()

    opt = LevMar()
    opt.verbose = 0
    opt.ftol = 1e-15
    opt.xtol = 1e-15
    opt.gtol = 1e-15
    opt.epsfcn = 1e-15
    print(opt)

    vfit = Fit(dall, mall, stat=stat, method=opt)
    print(vfit)
    vres = vfit.fit()

    print()
    print()
    print("Did the fit succeed? [bool]")
    print(vres.succeeded)
    print()
    print()
    print(vres.format())

    # # =========================================
    # # Plotting after fit
    if silent is False:
        # Dataset 1
        fplot1 = FitPlot()
        mplot1.prepare(d1, model1)
        fplot1.prepare(dplot1, mplot1)
        fplot1.plot()

        # residual
        title = "Data 1"
        plt.title(title)
        plt.plot(wave1, flux1 - model1(wave1))
        plt.show()

        # Dataset 2
        fplot2 = FitPlot()
        mplot2.prepare(d2, model2)
        fplot2.prepare(dplot2, mplot2)
        fplot2.plot()

        # residual
        title = "Data 2"
        plt.title(title)
        plt.plot(wave2, flux2 - model2(wave2))
        plt.show()

        # both datasets - no residuals
        splot = SplitPlot()
        splot.addplot(fplot1)
        splot.addplot(fplot2)

        plt.tight_layout()
        plt.show()

    return model_list
Exemple #4
0
def fit(star_name, data, model, silent=False, breakdown=False):
    """A function that will fit a given multi-part model to a given spectrum.



    :param star_name: Name of the target star
    :type star_name: str
    :param data: Spectrum data in the form (wave, flux)
    :type data: tuple
    :param model: An unfit spectrum model
    :type model: object
    :param silent:  If true, no plots will generate, defaults to False
    :type silent: bool

    :return: model that is fit to the data
    :rtype: object


    """

    wave, flux = data

    # %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

    d = Data1D(star_name, wave, flux)

    # ==========================================
    # Initial guesses

    # Dataset 1
    dplot = DataPlot()
    dplot.prepare(d)
    if silent is False:
        dplot.plot()

    mplot = ModelPlot()
    mplot.prepare(d, model)
    if silent is False:
        dplot.plot()
        mplot.overplot()
        plt.show()

    # =========================================
    # Fitting happens here - don't break please
    start = time.time()

    stat = LeastSq()

    opt = LevMar()

    opt.verbose = 0
    opt.ftol = 1e-15
    opt.xtol = 1e-15
    opt.gtol = 1e-15
    opt.epsfcn = 1e-15

    if silent is False:
        print(opt)

    vfit = Fit(d, model, stat=stat, method=opt)

    if silent is False:
        print(vfit)

    vres = vfit.fit()

    if silent is False:
        print()
        print()
        print(vres.format())

    # =========================================
    # Plotting after fit

    # Dataset 1
    if silent is False:
        fplot = FitPlot()
        mplot.prepare(d, model)
        fplot.prepare(dplot, mplot)
        fplot.plot()

        # residual
        plt.title(star_name)
        plt.plot(wave, flux - model(wave))

        # plt.xaxis(fontsize = )
        plt.xlabel("Wavelength (AA)", fontsize=12)
        plt.ylabel("Flux", fontsize=12)
        plt.tick_params(axis="both", labelsize=12)

    if silent is False:
        duration = time.time() - start
        print()
        print("Time taken: " + str(duration))
        print()

    plt.show()

    if breakdown is True:
        params = []

        cont = model[0]

        if silent is False:
            plt.scatter(wave, flux, marker=".", c="black")
            plt.plot(wave, model(wave), c="C1")

        for line in model:
            if line.name[0] != "(":
                if line.name == "Cont_flux":
                    if silent is False:
                        print(line)
                        plt.plot(wave, line(wave), linestyle="--")
                else:
                    params.append(line)
                    if silent is False:
                        print()
                        print(line)
                        plt.plot(wave, line(wave) * cont(wave), linestyle="--")

        plt.show()

        return model, params

    return model
Exemple #5
0
# Note: can not print(dplot) as there is a problem with the fact
#       the input to the data object is a list, not ndarray
#       Sherpa 4.10.0

from sherpa.models.basic import Polynom1D
mdl = Polynom1D()
report("print(mdl)")

mdl.c2.thaw()

from sherpa.plot import ModelPlot
mplot = ModelPlot()
mplot.prepare(d, mdl)
dplot.plot()
mplot.overplot()
savefig("data_model_initial.png")

from sherpa.stats import LeastSq
from sherpa.optmethods import NelderMead
from sherpa.fit import Fit
f = Fit(d, mdl, stat=LeastSq(), method=NelderMead())
report("print(f)")

res = f.fit()
dump("res.succeeded")

report("res.format()")
report("res")

report("mdl")