Monday, February 28, 2011

BOSS Mask Problem?

Below is an email I sent to Martin White today after Shirley, Nic and David couldn't figure out what I was doing wrong with my masks/randoms:

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Martin,
Back in December you generated a polygon mask for me for the BOSS data. I've been using this mask + BOSS data for my reconstruction project with Alexia and have gotten puzzling results when I compute correlation functions on the data.

This prompted me to look more closely at the way I was applying the mask to make sure I wasn't making a stupid mistake.

The BOSS data inside the mask (with weights greater than 0) looks very patchy up close, and both Ross and Schlegel think it shouldn't look like this.

I was wondering if you could look at the attached plots and see if you think the mask is being applied correctly.

MaskedBOSSDataAll.png shows the entire footprint. The blue points are galaxies in the spAll file that were outside the mask or have a weight = 0. The red points are galaxies in the spAll file that were inside the mask and have a weight GT 0.


MaskedBOSSDataClose.png shows a zoom into the region (35 < Dec < 55, 110 < RA < 130). The color scheme is the same as above. This shows the strange "patchy" nature of the masked data even in regions which seem to have been observed. I tried to use the same ra/dec range as Fig 3 from your paper (http://arxiv.org/PS_cache/arxiv/pdf/1010/1010.4915v2.pdf) for easy comparison.


One difference between my data and that in your plot is that the weights (completeness) of the red objects in my plots range from [0.75 to 1.0], whereas in your paper's plot they seem to range from [0 to 1.0]. Perhaps this is how you determined what is in the mask, if it had a spectroscopic completeness greater than 0.75?

If you have any insight into what I am doing wrong, that would be really helpful. Below is the IDL code I am using to apply the masks and generate the attached plots.

Thank you,
Jessica

;Here the code I used to apply the mask:
;Read in BOSS data
bossgalaxies = '/clusterfs/riemann/raid001/jessica/boss/spAll-v5_4_14.fits'
spall = mrdfits(bossgalaxies, 1)

;Trim to be a galaxy
isgal = where(spall.specprimary EQ 1 $
AND (spall.boss_target1 AND 2L^0+2L^1+2L^2+2L^3+2L^7) NE 0 $
AND strmatch(spall.class,'GALAXY*') $
AND spall.zwarning EQ 0)

;Select galaxies
galaxies = spall[isgal]
ra = galaxies.ra
dec = galaxies.dec
z = galaxies.z
spall = 0

bossmask = "/clusterfs/riemann/raid001/jessica/boss/bossX.002.ply"
read_mangle_polygons, bossmask, polygons, id
results = is_in_window(ra=ra,dec=dec,polygons,in_polygon=polynum)
inBossMask = where(results GT 0)
polys = polynum[inBossMask]
bossWeight = polygons[polys].weight
;Cut the Ra/Dec/z such that it is in the Shirley Mask
sra = ra[inBossMask]
sdec = dec[inBossMask]
sz = z[inBossMask]

;Here is the code I used to make the attached plots
;Plot Data that is inside the mask
window,xsize=700,ysize=600
xobject = sra
yobject = sdec
xtit = 'RA'
ytit = 'Dec'
mtit = 'SDSS BOSS Data w/ and w/o Mask'
plot, xobject, yobject, psym=3, symsize=2, xrange = [130,110], yrange=[35,55], XTITLE = xtit, YTITLE = ytit, TITLE = mtit, charsize = 2, charthick = 1, thick = 2, xthick=2, ythick=2
oplot, ra, dec, ps=3, color=fsc_color('blue')
thisweight = where(bossWeight GT 0)
oplot, xobject[thisWeight], yobject[thisWeight], ps=3, color=fsc_color('red')


plot, xobject, yobject, psym=3, symsize=2, xrange = [0,360], yrange=[0,60], XTITLE = xtit, YTITLE = ytit, TITLE = mtit, charsize = 2, charthick = 1, thick = 2, xthick=2, ythick=2
oplot, ra, dec, ps=3, color=fsc_color('blue')
thisweight = where(bossWeight GT 0)
oplot, xobject[thisWeight], yobject[thisWeight], ps=3, color=fsc_color('red')

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