Beispiel #1
0
def simulate_LSST(id, p, a, path, noise, tmin=3, tmax=30, dur=10, plot=False):
    """ Photometry with precision of 10 ppm (?).
    Uneven time sampling that ranges (uniformily) from 3 to 30 days (?).
    Lasting 10 years (?).
    id: id of the star.
    p: rotation period in seconds
    a: amplitude in ppm
    path: path to save files
    tmin, tmax: min and max intervals between observations in days.
    dur: duration in years.
    noise: noise level (ppm). Default is 10 ppm.
    """
    print(id)
    id = str(int(id)).zfill(4)

#     # only make new simulation if one doesn't already exist
#     if os.path.exists("simulations/{0}".format(id)):
#         return

    # The time array
#     x = np.cumsum(np.random.uniform(tmin, tmax, 1000))
#     x = x[x < dur * 365.25]
#     x = generate_visits()
#     x += -x[0]
    x, depth = np.genfromtxt("{0}_cadence.txt".format(path)).T

#     sin2incl = np.random.uniform(np.sin(0)**2, np.sin(np.pi/2)**2)
#     incl = np.arcsin(sin2incl**.5)
#     tau = np.exp(np.random.uniform(np.log(p), np.log(10*p)))
#     res0, res1 = mklc.mklc(x, incl=incl, tau=tau, p=p)
    res0, res1 = mklc.mklc(x, p=p)
    nspot, ff, amp_err = res0
    time, area_tot, dF_tot, dF_tot0 = res1
    noise_free_y = dF_tot0 / np.median(dF_tot0) - 1
    y = dF_tot0 / np.median(dF_tot0) - 1 + noise*1e-6 * np.random.randn(len(x))
    yerr = np.ones_like(y) * noise * 1e-6

    data = np.vstack((x, y, yerr))
    np.savetxt("{0}/{1}.txt".format(path, id), data.T)
    truths = np.array([p, a])
    truths = np.vstack((np.array([p]), np.array([a])))
    f = open("{0}/all_truths.txt".format(path), "a")
    np.savetxt(f, truths.T)
    f.close()

    if plot:
        print("plotting light curve")
        plt.clf()
        plt.errorbar(x/365.25, y, yerr=yerr, fmt="k.", capsize=0, ecolor=".5")
        plt.xlabel("$\mathrm{Time~(years)}$")
        plt.ylabel("$\mathrm{Normalised~Flux}$")
        plt.xlim(min(x/365.25), max(x/365.25))
        plt.subplots_adjust(left=.2, bottom=.12)
        plt.savefig("{0}/{1}.pdf".format(path, id))
def simulate(id, pmin=0.5, pmax=100.0, amin=1e-3, amax=1e-1, nsim=100, gen_type="s", kepler=False, plot=False):
    """
    pmin and pmax in days, amin and amax in ppm.
    """
    periods = np.exp(np.random.uniform(np.log(pmin), np.log(pmax), nsim))
    amps = np.exp(np.random.uniform(np.log(amin), np.log(amax), nsim))
    np.savetxt("simulations/true_periods.txt", np.transpose((np.arange(nsim), periods, amps)))
    thetas = np.zeros((nsim, 5))
    thetas[:, 0] = np.exp(np.random.uniform(-6, -4))
    thetas[:, 1] = np.exp(np.random.uniform(4, 7))
    thetas[:, 2] = np.exp(np.random.uniform(-1.5, 1.5))
    thetas[:, 3] = np.exp(np.random.uniform(-11, -8))
    thetas[:, 4] = periods

    # load test star data FIXME: I'm just using the time values
    # because this is not a quiet star
    #     x, y, yerr = np.genfromtxt("%s_lc.txt" % id).T
    #         time = x
    #     else: time = np.arange(0, x[-1]-x[0], .02043365)
    time = np.arange(0, 1600, 0.02043365)

    std = 1e-5
    yerr = np.ones_like(time) * std
    flux = np.zeros_like(time) + np.random.randn(len(time)) * std

    for i, p in enumerate(periods):
        print i, "of ", len(periods), "\n"
        print "amps = ", amps[i]
        if gen_type == "s":
            res0, res1 = mklc.mklc(time, p=p)
            nspot, ff, amp_err = res0
            time, area_tot, dF_tot, dF_tot0 = res1
            simflux = dF_tot0 / np.median(dF_tot0) - 1
        elif gen_type == "GP":
            k = thetas[i, 0] * ExpSquaredKernel(thetas[i, 1]) * ExpSine2Kernel(
                thetas[i, 2], thetas[i, 4]
            ) + WhiteKernel(std)
            gp = george.gp()
            gp.compute(time, yerr)
            simflux = gp.sample()

        np.savetxt("simulations/%s_%s.txt" % (str(int(i)).zfill(4), gen_type), np.transpose((time, simflux)))

        if plot:
            plt.clf()
            plt.plot(time, simflux * amps[i] + flux, "k.")
            plt.savefig("simulations/%s%s" % (i, gen_type))
            plt.title("p = %s, a = %s" % (p, amps[i]))
            assert 0
Beispiel #3
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def inject_star_spots(raw_x, periods):
    amps = []
    for i, p in enumerate(periods):
        # generate injection
        nspot = 200
        incl = np.pi*5./12.
        amp = 1.
        tau = 30.5
        res0, res1 = mklc(raw_x, nspot, incl, amp, tau, p)
        time = res1[0]
        flux = res1[2]/np.median(res1[2]) - 1
        np.savetxt("injections/%s_lc.txt" % str(i).zfill(4),
                   np.transpose((time, flux)))
        amps.append(res0[-1])
    np.savetxt("injections/truth.txt", np.transpose((range(len(periods)),
               periods, np.array(amps))))
Beispiel #4
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def simulate(EPIC, c=1, pmin=.5, pmax=100., amin=1e-3, amax=1e-1,
             nsim=1000, usereal=False):
    """
    pmin and pmax in days, amin and amax in ppm.
    """
    periods = np.exp(np.random.uniform(np.log(pmin), np.log(pmax), nsim))
    amps = np.exp(np.random.uniform(np.log(amin), np.log(amax), nsim))
    np.savetxt("true_periods.txt", np.transpose((np.arange(1000), periods,
               amps)))

    # load test star data
    fname = "hlsp_k2sff_k2_lightcurve_%s-c0%s_kepler_v1_llc.fits" % (EPIC, c)
    dname = "/export/bbq1/angusr/data/vanderburgC%s/%s" % (c, fname)
    data = fitsio.read(dname)
    time, raw, flux = [np.zeros(len(data)) for i in range(3)]
    for i in range(len(data)):
        time[i] = data[i][0]
        raw[i] = data[i][1]
        flux[i] = data[i][2] - 1

    if usereal:
        # fit and remove straight line
        AT = np.vstack((time, np.ones_like(time)))
        ATA = np.dot(AT, AT.T)
        m, c = np.dot(np.linalg.inv(ATA), np.dot(AT, flux))
        flux -= (m*time+c)

    std = np.std(flux)
    flux = np.zeros_like(time) + np.random.randn(len(time))*std

    for i, p in enumerate(periods):
        print i, "of ", len(periods), "\n"
        print "amps = ", amps[i]
        res0, res1 = mklc.mklc(time, p=p)
        nspot, ff, amp_err = res0
        time, area_tot, dF_tot, dF_tot0 = res1
        simflux = dF_tot0 / np.median(dF_tot0) - 1

        np.savetxt("simulations/%s.txt" % i, np.transpose((time, simflux)))

        plt.clf()
        plt.plot(time, simflux*amps[i]+flux, "k.")
        plt.savefig("simulations/%s" % i)
        plt.title("p = %s, a = %s" % (p, amps[i]))
Beispiel #5
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def generate_lcs(x, y, id, N, nspot_min=50, nspot_max=500, incl_min=0,
                 incl_max=np.pi/4., amp_min=1, amp_max=100, pmin=.5,
                 pmax=90, tau_min=5, tau_max=20):
    """
    Generate N fake light curves based on the parameter limits.
    x (array): times of k2 lc.
    N (int): number of lcs.
    returns 2d array of light curves, the k2 light curve and a dictionary of
    true parameters.
    """

    params = [nspot_min, nspot_max, incl_min, incl_max, amp_min*rvar,
              amp_max*rvar, pmin, pmax, tau_min, tau_max]
    nspots, incl, periods, amps, tau = injection_params(N, params)
    true_params = {'nspots': nspots, 'incl': incl, 'periods': periods,
                   'amps': amps, 'tau': tau}

    xarr = np.zeros((len(x), N))
    yarr = np.zeros((len(x), N))
    for i in range(N):
        print(i, "of", N)
        res0, res1 = mklc(x, nspot=nspots[i], incl=incl[i], tau=tau[i],
                          p=periods[i])
        med = np.median(res1[2, :])
        ys = (res1[2, :] / med - 1) * amps[i]  # median normalise and scale
        yarr[:, i] = ys + y
        xarr[:, i] = x
    if N == 1:
        return xarr.T[0], yarr.T[0], x, y, true_params

    # save the results
    np.savetxt("lcs.txt", yarr.T)
    np.savetxt("xs.txt", xarr.T)
    np.savetxt("truth.txt", np.vstack((nspots, incl, periods, amps, tau)).T)

    return xarr, yarr, true_params
Beispiel #6
0
def simulate_LSST(x, depth, filt, id, p, a, path, noise, tmin=3, tmax=30,
                  dur=10, plot=False):
    """ Photometry with precision of 10 ppm (?).
    Uneven time sampling that ranges (uniformily) from 3 to 30 days (?).
    Lasting 10 years (?).
    id: id of the star.
    p: rotation period in seconds
    a: amplitude in ppm
    path: path to save files
    tmin, tmax: min and max intervals between observations in days.
    dur: duration in years.
    noise: noise level (ppm). Default is 10 ppm.
    """
    print(id)
    id = str(int(id)).zfill(4)

    sin2incl = np.random.uniform(np.sin(0)**2, np.sin(np.pi/2)**2)
    incl = np.arcsin(sin2incl**.5)
    tau = np.exp(np.random.uniform(np.log(p), np.log(10*p)))
    res0, res1 = mklc.mklc(x, incl=incl, tau=tau, p=p)
    # res0, res1 = mklc.mklc(x, p=p)
    nspot, ff, amp_err = res0
    time, area_tot, dF_tot, dF_tot0 = res1
    noise_free_y = dF_tot0 / np.median(dF_tot0) - 1
    y = dF_tot0 / np.median(dF_tot0) - 1 + noise*1e-6 * \
        np.random.randn(len(x))
    yerr = np.ones(len(y)) * noise * 1e-6

    data = np.vstack((x, y, yerr))
    np.savetxt("{0}/{1}.txt".format(path, id), data.T)
    # truths = np.array([p, a])
    # truths = np.vstack((np.array([p]), np.array([a])))
    # np.savetxt(f, truths.T)
    f = open("{0}/all_truths.txt".format(path), "a")
    f.write("{0} {1}\n".format(p, a))
    f.close()

    if plot:
        u = filt == "u"
        g = filt == "g"
        r = filt == "r"
        i = filt == "i"
        z = filt == "z"
        y = filt == "y"
        print("plotting light curve")
        plt.clf()
        plt.errorbar(x[u]/365.25, y[u], yerr=yerr[u], fmt=".", capsize=0,
                     ecolor=".5", color="b", label="u")
        plt.errorbar(x[g]/365.25, y[g], yerr=yerr[g], fmt=".", capsize=0,
                     ecolor=".5", color="g", label="g")
        plt.errorbar(x[r]/365.25, y[r], yerr=yerr[r], fmt=".", capsize=0,
                     ecolor=".5", color="r", label="r")
        plt.errorbar(x[i]/365.25, y[i], yerr=yerr[i], fmt=".", capsize=0,
                     ecolor=".5", color="m", label="i")
        plt.errorbar(x[z]/365.25, y[z], yerr=yerr[z], fmt=".", capsize=0,
                     ecolor=".5", color="y", label="z")
        plt.errorbar(x[y]/365.25, y[y], yerr=yerr[y], fmt=".", capsize=0,
                     ecolor=".5", color="k", label="y")
        plt.xlabel("$\mathrm{Time~(years)}$")
        plt.ylabel("$\mathrm{Normalised~Flux}$")
        plt.xlim(min(x/365.25), max(x/365.25))
        plt.subplots_adjust(left=.2, bottom=.12)
        plt.savefig(os.path.join(path, "{}".format(id)))