diff options
Diffstat (limited to 'astro')
| -rwxr-xr-x | astro/ps2d.py | 48 |
1 files changed, 43 insertions, 5 deletions
diff --git a/astro/ps2d.py b/astro/ps2d.py index 4177d43..e3548b8 100755 --- a/astro/ps2d.py +++ b/astro/ps2d.py @@ -93,6 +93,9 @@ class PS2D: cube image pixel size [arcsec] frequencies : 1D `~numpy.ndarray` frequencies at each image slice [MHz] + meanstd : bool, optional + if ``True``, calculate the mean and standard deviation for each + power bin instead of the median and 68% IQR. window_name : str, optional if specified, taper the cube along the frequency axis using the specified window. @@ -102,7 +105,7 @@ class PS2D: unit of the cube data; will be used to determine the power spectrum unit as well as the plot labels. """ - def __init__(self, cube, pixelsize, frequencies, + def __init__(self, cube, pixelsize, frequencies, meanstd=False, window_name=None, window_width="extended", unit="???"): logger.info("Initializing PS2D instance ...") self.cube = np.array(cube, dtype=float) @@ -131,6 +134,7 @@ class PS2D: # Transverse comoving distance at zc; unit: [Mpc] self.DMz = cosmo.comoving_transverse_distance(self.zc).value + self.meanstd = meanstd self.window_name = window_name self.window_width = window_width self.window = self.gen_window(name=window_name, width=window_width) @@ -184,11 +188,23 @@ class PS2D: """ Calculate the 2D power spectrum by cylindrically binning the above 3D power spectrum. + + Returns + ------- + ps2d : 3D `~numpy.ndarray` + 3D array of shape (3, n_k_los, n_k_perp) including the median + and lower and upper errors (68% IQR) at each power bin. + If ``self.meanstd=True`` then the mean and standard deviation + are calculated instead. + + Attributes + ---------- + ps2d """ logger.info("Calculating 2D power spectrum ...") n_k_perp = len(self.k_perp) n_k_los = len(self.k_los) - ps2d = np.zeros(shape=(n_k_los, n_k_perp)) # (k_los, k_perp) + ps2d = np.zeros(shape=(3, n_k_los, n_k_perp)) # value, errl, erru eps = 1e-8 ic_xy = (np.abs(self.k_xy) < eps).nonzero()[0][0] @@ -205,7 +221,16 @@ class PS2D: for s in range(n_k_los): iz = (p_z == s).nonzero()[0] cells = np.concatenate([self.ps3d[z, iy, ix] for z in iz]) - ps2d[s, r] = cells.mean() + if self.meanstd: + ps2d[0, s, r] = cells.mean() + std = cells.std() + ps2d[1, s, r] = std + ps2d[2, s, r] = std + else: + median, q16, q84 = np.percentile(cells, q=(50, 16, 84)) + ps2d[0, s, r] = median + ps2d[1, s, r] = median - q16 + ps2d[2, s, r] = q84 - median self.ps2d = ps2d return ps2d @@ -227,7 +252,8 @@ class PS2D: """ x = self.k_perp y = self.k_los - mappable = ax.pcolormesh(x[1:], y[1:], np.log10(self.ps2d[1:, 1:]), + mappable = ax.pcolormesh(x[1:], y[1:], + np.log10(self.ps2d[0, 1:, 1:]), cmap="jet") ax.set(xscale="log", yscale="log", xlim=(x[1], x[-1]), ylim=(y[1], y[-1]), @@ -389,6 +415,11 @@ class PS2D: hdr["CONTENT"] = ("2D cylindrically averaged power spectrum", "data product") hdr["BUNIT"] = ("%s^2 Mpc^3" % self.unit, "data unit") + if self.meanstd: + hdr["AvgType"] = ("mean + standard deviation", "average type") + else: + hdr["AvgType"] = ("median + 68% IQR", "average type") + # Physical coordinates: IRAF LTM/LTV # Li{Image} = LTMi_i * Pi{Physical} + LTVi # Reference: ftp://iraf.noao.edu/iraf/web/projects/fitswcs/specwcs.html @@ -396,6 +427,7 @@ class PS2D: hdr["LTM1_1"] = 1.0 / dk_xy hdr["LTV2"] = 0.0 hdr["LTM2_2"] = 1.0 / dk_z + # WCS physical coordinates hdr["WCSTY1P"] = "PHYSICAL" hdr["CTYPE1P"] = ("k_perp", "wavenumbers perpendicular to LoS") @@ -409,6 +441,7 @@ class PS2D: hdr["CRVAL2P"] = (0.0, "coordinate of the reference pixel") hdr["CDELT2P"] = (dk_z, "coordinate delta/step") hdr["CUNIT2P"] = ("Mpc^-1", "coordinate unit") + # Data information hdr["PixSize"] = (self.pixelsize, "[arcsec] data cube pixel size") hdr["Z_C"] = (self.zc, "data cube central redshift") @@ -428,6 +461,11 @@ def main(): parser.add_argument("-C", "--clobber", dest="clobber", action="store_true", help="overwrite existing file") + parser.add_argument("-m", "--mean-std", dest="meanstd", + action="store_true", + help="calculate the mean and standard deviation " + + "for each averaged annulus instead of the median " + + "16%% and 84%% percentiles (i.e., 68%% IQR)") parser.add_argument("-P", "--plot", dest="plot", action="store_true", help="plot the 2D power spectrum and save") @@ -473,7 +511,7 @@ def main(): pixelsize = abs(wcs.wcs.cdelt[0]) * 3600 # [deg] -> [arcsec] ps2d = PS2D(cube=cube, pixelsize=pixelsize, frequencies=frequencies, - window_name=args.window, unit=bunit) + meanstd=args.meanstd, window_name=args.window, unit=bunit) ps2d.calc_ps3d() ps2d.calc_ps2d() ps2d.save(outfile=args.outfile, clobber=args.clobber) |