At Los Alamos

I am visiting Alexia at Los Alamos National Lab for the next three weeks. Los Alamos is beautiful, but COLD.

I'm putting the final touches on the data-correlation function setup.

I noticed that in the 3D auto-correlation, I am producing two different random catalogs and using the following calculation:

(dd -dr1 -r2d +r1r2)/(r1r2)

This might be extra computing power than necessary if it is ok for r1 = r2... but I forget if they need to be different... perhaps they do need to be different in order for this to work. It seems like this is something I would have thought of before.

I talked to Alexia about this and she thinks it shouldn't make a difference either way. So I am going to set r1 = r2 and see what happens....

Old Autocorrelation Function results (without randoms fed in)
# r (Mpc/h) cross xi (r)
# r (Mpc/h) cross xi (r)
1.0009750000 113.0999999998
3.0009250000 4.3312368973
5.0008750000 0.1890557940
7.0008250000 0.3768587361
9.0007750000 0.4359240581
11.0007250000 0.1349752029
13.0006750000 0.1273595140
15.0006250000 -0.1351841518
17.0005750000 0.2378351539
19.0005250000 0.2994336370
21.0004750000 -0.0479553597
23.0004250000 -0.0998846930
25.0003750000 -0.1438266200
27.0003250000 -0.3070417433
29.0002750000 -0.3108741254
31.0002250000 -0.1177777522
33.0001750000 -0.0633376228
35.0001250000 -0.2604527820
37.0000750000 -0.2517495550
39.0000250000 -0.0304629134


New Autocorrelation Function results (with randoms fed in)
I think small differences are rounding errors
# Reached checkpoint 4
# r (Mpc/h) cross xi (r)
1.0009750000 113.0999999998
3.0009250000 4.3294918806
5.0008750000 0.1890963726
7.0008250000 0.3766263941
9.0007750000 0.4359240581
11.0007250000 0.1349752029
13.0006750000 0.1273650408
15.0006250000 -0.1355281973
17.0005750000 0.2380827199
19.0005250000 0.2995001354
21.0004750000 -0.0479749624
23.0004250000 -0.0998864926
25.0003750000 -0.1437953465
27.0003250000 -0.3070974753
29.0002750000 -0.3107744869
31.0002250000 -0.1177689518
33.0001750000 -0.0632545877
35.0001250000 -0.2605975485
37.0000750000 -0.2517029624
39.0000250000 -0.0304363094

New Autocorrelation Function with r1 = r2 (with randoms fed in)
There are pretty big difference between these two, but this could just be because my data set is small. Should check on a larger set.
# Reached checkpoint 4
# r (Mpc/h) cross xi (r)
1.0009750000 120.9999999998
3.0009250000 3.9579487179
5.0008750000 0.1234024722
7.0008250000 0.3826803206
9.0007750000 0.4731333382
11.0007250000 0.0871628790
13.0006750000 0.0808080808
15.0006250000 -0.1168749344
17.0005750000 0.2334021835
19.0005250000 0.3148748159
21.0004750000 -0.0339674194
23.0004250000 -0.0762365727
25.0003750000 -0.1365716955
27.0003250000 -0.2876355988
29.0002750000 -0.3209356312
31.0002250000 -0.1164599148
33.0001750000 -0.0517181534
35.0001250000 -0.2402264337
37.0000750000 -0.2732306595
39.0000250000 -0.0168706759