i_age = 170 p.plot(ssp_wave, ssp_flux[i_age], hold=False) p.xlim(1800., 11000.) # Pick out some wavelength range of interest: # Nah, not worth it... #lam_lo = 1750. #lam_hi = 11000. #ilam_lo = min(n.where(ssp_wave >= lam_lo)[0]) #ilam_hi = max(n.where(ssp_wave <= lam_hi)[0]) # Does a blur matrix at this stage give us something tractable? vdisp = 225. # (in km/s) c_in_km_per_s = 299792.458 sigconv = ssp_wave * vdisp / c_in_km_per_s ssp_bound = pxs.cen2bound(ssp_wave) gblur = pxs.gauss_blur_matrix(ssp_bound, sigconv) ssp_blur = gblur * ssp_flux[i_age] p.plot(ssp_wave, ssp_flux[i_age], hold=False) p.plot(ssp_wave, ssp_blur, hold=True) p.xlim(1800., 11000.) # Looks good. # Now let's bin it down to the BOSS coadd resoultion # and dial in the wavelength range we want. sspSpline = pxs.PixelSpline(ssp_bound, ssp_blur) ssp_coeff0 = 3.225 ssp_coeff1 = 0.0001 ssp_naxis1 = 2**13
p.plot(ssp_wave, ssp_flux[i_age], hold=False) p.xlim(1800.,11000.) # Pick out some wavelength range of interest: # Nah, not worth it... #lam_lo = 1750. #lam_hi = 11000. #ilam_lo = min(n.where(ssp_wave >= lam_lo)[0]) #ilam_hi = max(n.where(ssp_wave <= lam_hi)[0]) # Does a blur matrix at this stage give us something tractable? vdisp = 225. # (in km/s) c_in_km_per_s = 299792.458 sigconv = ssp_wave * vdisp / c_in_km_per_s ssp_bound = pxs.cen2bound(ssp_wave) gblur = pxs.gauss_blur_matrix(ssp_bound, sigconv) ssp_blur = gblur * ssp_flux[i_age] p.plot(ssp_wave, ssp_flux[i_age], hold=False) p.plot(ssp_wave, ssp_blur, hold=True) p.xlim(1800.,11000.) # Looks good. # Now let's bin it down to the BOSS coadd resoultion # and dial in the wavelength range we want. sspSpline = pxs.PixelSpline(ssp_bound, ssp_blur) ssp_coeff0 = 3.225 ssp_coeff1 = 0.0001 ssp_naxis1 = 2**13
wave = 10.**loglam #i = -1L #i+=1 #p.plot(wave, flux[i], hold=False) # Choose a particular spectrum that you like, and have a look at it: istar = 40 p.plot(wave, flux[istar], hold=False, drawstyle='steps-mid') # Now initialize a "pixelspline" object for this spectrum. # If the units are f-lambda, then we really should use wavelength # and not log-wavelength as the baseline to initialize. # First convert the log-lambda pixel-center baseline # to a log-lambda pixel-boundary baseline: logbound = pxs.cen2bound(loglam) wavebound = 10.**logbound PS = pxs.PixelSpline(wavebound, flux[istar]) # Now let's try out a few of the methods... # First, let's do a point-evaluation of the pixel spline # over a finely gridded baseline: nsub = 10 nfine = npix * nsub # (The following line ensures that the first "nsub" points in logfine # have a mean value equal to the first single point in loglam, and so on.) logfine = coeff0 + coeff1 * (n.arange(nfine) - 0.5 * (nsub - 1)) / float(nsub) wavefine = 10.**logfine fluxfine = PS.point_evaluate(wavefine)
