cat anat2anatorig.mat
0x1p+0  0x0p+0  0x0p+0  0x0p+0
-0x0p+0  -0x0p+0  -0x1p+0  0x1.fep+7
0x0p+0  0x1p+0  0x0p+0  0x0p+0
0x0p+0  0x0p+0  0x0p+0  0x1p+0

cat anat2diff.bbr.mat
0x1.fffbcb7420fd8p-1  0x1.ef2c40cb30e0bp-10  -0x1.fd18c0eaf5b95p-8  0x1.9777b3c864bf5p+0
-0x1.73f8a907833c1p-9  0x1.fc0b72de1fa3dp-1  -0x1.fc04f41434057p-4  0x1.ffaa02b9b4ffcp+2
0x1.e9ce3c1e22462p-8  0x1.fc182ace528c7p-4  0x1.fc07e89cb943fp-1  -0x1.1b520e868fde2p+6
0x0p+0  0x0p+0  0x0p+0  0x1p+0

cat anat2mni.mat
0x1.124885caf6067p+0  0x1.92ce836178779p-7  -0x1.008fcced1b0d9p-5  -0x1.5f3de08b2ec91p+5
0x1.0de8a8dca27bap-9  0x1.fe0f292ef123p-1  0x1.0114c5a5df6f5p-10  -0x1.178742271c4a2p+4
0x1.d9381279249eep-5  0x1.b78712b08db16p-8  0x1.1f68d2e1e61acp+0  -0x1.434316c796504p+6
0x0p+0  0x0p+0  0x0p+0  0x1p+0

cat anatorig2anat.mat
   1.00000000    0.00000000    0.00000000    0.00000000
   0.00000000    0.00000000    1.00000000    0.00000000
   0.00000000   -1.00000000    0.00000000  255.00000000
   0.00000000    0.00000000    0.00000000    1.00000000

anat2diff.bbr.mat
goofy

anatorig2mni.mat
goofy

diff2anat.bbr.mat
goofy

diff2anatorig.bbr.mat
   0.99996817   -0.00283791    0.00747391   -1.03955317
   0.00776814    0.12402843   -0.99224871  183.71495056
   0.00188895    0.99227440    0.12404627    0.85021991
   0.00000000    0.00000000    0.00000000    1.00000000

and the rest of the .mat files are goofy. Now for some .dat and other files:
cat anatorig2diff.bbr.dat
hbot_subj2
2.000000
2.000000
0.150000
9.999679923057556e-01 -1.888935687020421e-03 7.768203038722277e-03 -8.427959084510803e-01
-7.473838515579700e-03 1.240464895963669e-01 9.922478795051575e-01 -6.980049610137939e+00
-2.837916370481253e-03 -9.922748804092407e-01 1.240281686186790e-01 9.108885765075684e+00
0 0 0 1
round

cat anat2anatorig.dat
1.000000
1.000000
0.150000
1.000000000000000e+00 0.000000000000000e+00 0.000000000000000e+00 0.000000000000000e+00
0.000000000000000e+00 0.000000000000000e+00 -1.000000000000000e+00 0.000000000000000e+00
0.000000000000000e+00 1.000000000000000e+00 0.000000000000000e+00 1.000000000000000e+00
0 0 0 1
round

cat anatorig2diff.bbr.dat.sum
$Id: mri_segreg.c,v 1.113 2016/05/10 03:23:20 greve Exp $
setenv SUBJECTS_DIR /export/research/analysis/human/jlewine/shared/jtdavis/DataDir
cd /export/research/analysis/human/jlewine/shared/jtdavis/DataDir
mri_segreg --mov /export/research/analysis/human/jlewine/shared/jtdavis/DataDir/tractDataDir/hbot_subj2/dmri/xfms/tmp.bbregister.4801/template.nii --init-reg /export/research/analysis/human/jlewine/shared/jtdavis/DataDir/tractDataDir/hbot_subj2/dmri/xfms/tmp.bbregister.4801/bbr.pass1.dat --out-reg /export/research/analysis/human/jlewine/shared/jtdavis/DataDir/tractDataDir/hbot_subj2/dmri/xfms/anatorig2diff.bbr.dat --interp trilinear --wm-proj-abs 2 --tol 1e-8 --tol1d 1e-3 --c0 0 --mincost /export/research/analysis/human/jlewine/shared/jtdavis/DataDir/tractDataDir/hbot_subj2/dmri/xfms/anatorig2diff.bbr.dat.mincost --dof 6 --nmax 36 --param /export/research/analysis/human/jlewine/shared/jtdavis/DataDir/tractDataDir/hbot_subj2/dmri/xfms/anatorig2diff.bbr.dat.param --surf white --brute -0.1 0.1 0.1 --cur-reg /export/research/analysis/human/jlewine/shared/jtdavis/DataDir/tractDataDir/hbot_subj2/dmri/xfms/tmp.bbregister.4801/reg.curopt.dat --gm-proj-frac 0.5 --nsub 1 --gm-gt-wm 0.5
sysname  Linux
hostname jupiter
machine  x86_64
user     jtdavis
movvol /export/research/analysis/human/jlewine/shared/jtdavis/DataDir/tractDataDir/hbot_subj2/dmri/xfms/tmp.bbregister.4801/template.nii
regfile /export/research/analysis/human/jlewine/shared/jtdavis/DataDir/tractDataDir/hbot_subj2/dmri/xfms/tmp.bbregister.4801/bbr.pass1.dat
subject hbot_subj2
dof 6
outregfile /export/research/analysis/human/jlewine/shared/jtdavis/DataDir/tractDataDir/hbot_subj2/dmri/xfms/anatorig2diff.bbr.dat
UseMask 0
UseLH 1
UseRH 1
nsubsamp 1
PenaltySign  -1
PenaltySlope 0.500000
PenaltyCenter 0.000000
surfname white
GMProjFrac 0.500000
WMProjAbs 2.000000
lhcostfile (null)
rhcostfile (null)
interp  trilinear (1)
frame  0
TolPowell 0.000000
nMaxItersPowell 36
n1dmin  3
Profile   0
Gdiag_no  -1
AddNoise  0 (0)
SynthSeed 1519523634
TransRandMax 0.000000
RotRandMax 0.000000
Translations 0.000000 0.000000 0.000000
Rotations   0.000000 0.000000 0.000000
Input reg
 0.99995  -0.00004   0.01010  -1.05560;
-0.01001   0.12659   0.99190  -6.84404;
-0.00132  -0.99196   0.12658   8.92347;
 0.00000   0.00000   0.00000   1.00000;

Initial costs ----------------
Number of surface hits 307222
WM  Intensity0   492.7537 +/- 129.7195
Ctx Intensity0   601.4268 +/- 158.7433
Pct Contrast0     19.2622 +/-  22.6817
Cost   0.2436
RelCost   0.2410

Brute force preopt -0.1 0.1 0.1, n = 729
     0  -0.1000  -0.1000  -0.1000  -0.1000  -0.1000  -0.1000      0.2343   0.2343  0.0
     3  -0.1000  -0.1000  -0.1000  -0.1000   0.0000  -0.1000      0.2318   0.2318  0.0
     6  -0.1000  -0.1000  -0.1000  -0.1000   0.1000  -0.1000      0.2306   0.2306  0.0
    33  -0.1000  -0.1000   0.0000  -0.1000   0.1000  -0.1000      0.2295   0.2295  0.0
    34  -0.1000  -0.1000   0.0000  -0.1000   0.1000   0.0000      0.2294   0.2294  0.0
    43  -0.1000  -0.1000   0.0000   0.0000   0.1000   0.0000      0.2290   0.2290  0.0
   274   0.0000  -0.1000   0.0000  -0.1000   0.0000   0.0000      0.2279   0.2279  0.0
   364   0.0000   0.0000   0.0000   0.0000   0.0000   0.0000      0.2278   0.2278  0.0
   542   0.1000  -0.1000   0.1000  -0.1000  -0.1000   0.1000      0.2267   0.2267  0.0

Final costs ----------------
Number of surface hits 307222
WM  Intensity0   491.6879 +/- 129.1284
Ctx Intensity0   599.8796 +/- 157.4317
Pct Contrast0     19.2305 +/-  22.5616
Cost   0.2385
RelCost   0.2410
Number of iterations     7
Min cost was 0.238505
RelMinCost   0.2360
Number of FunctionCalls   511
OptimizationTime 106.266000 sec
Parameters at optimum (transmm, rotdeg)
 0.18168 -0.15625  0.16631 -0.14663  0.08831  0.14558
Number of surface hits 307222
WM  Intensity   491.6879 +/- 129.1284
Ctx Intensity   599.8796 +/- 157.4317
Pct Contrast     19.2305 +/-  22.5616
Cost at optimum   0.2385
RelCostOptimum   0.2360
nhits= 307222 wmmn=  491.6879 wmstd=129.1284 constd=   22.5616 ctxmn=  599.8796 ctxstd=157.4317 conmn =  19.2305 costmn =   0.2385
#C#   0.182  -0.156   0.166 -0.147  0.088  0.146 0.000000 0.000000 0.238505 491.687877 599.879620 19.230492 0.000000 0.500000     1 0
Reg at min cost was
 0.99997  -0.00189   0.00777  -0.84280;
-0.00747   0.12405   0.99225  -6.98005;
-0.00284  -0.99227   0.12403   9.10889;
 0.00000   0.00000   0.00000   1.00000;

Original Reg - Optimal Reg
-0.00002   0.00184   0.00233  -0.21280;
-0.00254   0.00254  -0.00034   0.13601;
 0.00152   0.00032   0.00255  -0.18541;
 0.00000   0.00000   0.00000   0.00000;

Surface-RMS-Diff-mm 0.299582 0.102872 0.532339