def zeroVelocityMocks():
sigmastar2 = 250.0 ** 2
# -------------------- Read in 6dFGSv data ----------------------
Dz, xerr, x_arr, y_arr, z_arr, xobs, r_arr, ngal = readin6dFGSvData()
# Calculate velocity uncertainties sigma_v from Eq. (10) of Scrimgeour et al. (2015)
sigma_v = 0.324 * 100.0 * Dz
# Calculate Dec (np array)
Dec = getDec(x_arr, y_arr, z_arr)
# Index of galaxies in Great Circle.
inC = np.where(Dec > -20.0)[0]
# ---------------------- Convert Dz to z -------------------------
zfile = "/Users/Morag/Cosmology_codes/redshift_OM0.3175.dat"
zo = cc.z_x_arr(Dz, zfile)
# -------- Assign each galaxy zero x, perturbed by xerr ----------
# Give all galaxies v=0 but perturb x by xerr
# Generate array of num random deltax values with std dev = xerr[gal]
BFArr = []
for i in xrange(100):
print i
x = xerr * np.random.standard_normal(ngal)
## Calibrate zeropoint to 0
# Mean x in Great Circle
# meanx = np.mean(x[inC])
# Subtract this from all galaxies
# x -= meanx
# Calculate derived Dr
Dr_der = Dz / 10 ** x
# Calculate new derived redshifts
zr_der = cc.z_x_arr(Dr_der, zfile)
vp_rand = speedlight * ((zo - zr_der) / (1.0 + zr_der))
# ------------------------- Calculate BF ---------------------------
# u = MLE_BF(x_arr, y_arr, z_arr, r_arr, vp_rand, sigma_v, sigmastar2)
u = MV_BF_6dFGSv(vp_rand)
BFArr.append((u[0], u[1], u[2]))
print ""
meanBF, stdBF = meanVector(BFArr)
print "Mean spurious BF: (%d pm %d, %d pm %d, %d pm %d)" % (
meanBF[0],
stdBF[0],
meanBF[1],
stdBF[1],
meanBF[2],
stdBF[2],
)
return
def x_to_v(x, z_obs, Dz, zfile):
Dr_der = Dz / 10.**x
zr_der = cc.z_x_arr(Dr_der, zfile)
v = speedlight * ((z_obs - zr_der)/(1.+zr_der))
return v
