Thank you, Eleanor!
I'll try pointless. In my case, the Sigma increase as i merge all the
five data while I/sigma decrease, which is opposite to what you
describe. Is this abnormal?
Fengyun
Quoting Eleanor Dodson <eleanor.dod...@york.ac.uk>:
All this is best done from the GUI - pointless will sort out batch
numbers, check indexing etc..
But you still have to identify any rogue batches, and decide on when
to jettison the data st..
The Sigma level is related to the number of observations of each
reflection, so this will decrease as the number of observations
increases, and therefor I/Sigma will increase..
Eleanor
On 16 Jul 2012, at 14:54, Fengyun Ni wrote:
Hi all,
I have to merge several datasets from different crystals because
the crystals suffer from severe radiation damage.
I read some previous posts and follow the protocol as described,
1) individually process the data;
2) scaleit to compare the Rfactors between different datasets;
3) renumber the batch number;
4) for those with low R-factor files (below 0.25), sort them;
5) scala the sorted file.
the script i used for the SCALA is,
scales batch brotaion spacing 5
which is the one in CCP4 example script that recommended for
synchrontron data.
For the first four dataset that are all cutoff to about 3.0A based
on I/sigI, and the statistics are like this,
N 1/d^2 Dmin(A) Rmrg Rfull Rcum Av_I SIGMA I/sigma
$$
1 0.0111 9.49 0.038 0.030 0.038 1934 125.2 15.5
2 0.0222 6.71 0.050 0.009 0.044 1182 92.4 12.8
3 0.0333 5.48 0.086 0.018 0.055 565 71.0 8.0
4 0.0444 4.74 0.093 0.166 0.065 724 100.2 7.2
5 0.0556 4.24 0.105 0.139 0.074 746 116.9 6.4
6 0.0667 3.87 0.143 0.058 0.085 522 105.4 5.0
7 0.0778 3.59 0.217 0.142 0.098 358 107.8 3.3
8 0.0889 3.35 0.365 0.265 0.115 216 109.5 2.0
9 0.1000 3.16 0.634 2.509 0.134 126 110.0 1.1
10 0.1111 3.00 0.965 10.157 0.154 81 109.8 0.7
For the fifth data cutoff to 2.76A, the stastics for the single
data is like this,
N 1/d^2 Dmin(A) Rmrg Rfull Rcum Av_I SIGMA I/sigma
$$
1 0.0131 8.73 0.031 0.036 0.031 6866 416.2 16.5
2 0.0263 6.17 0.034 0.036 0.032 2994 185.5 16.1
3 0.0394 5.04 0.039 0.040 0.034 2327 185.5 12.5
4 0.0525 4.36 0.039 0.045 0.036 3358 249.6 13.5
5 0.0656 3.90 0.047 0.048 0.038 2226 184.2 12.1
6 0.0788 3.56 0.064 0.059 0.041 1390 151.7 9.2
7 0.0919 3.30 0.101 0.084 0.045 787 118.0 6.7
8 0.1050 3.09 0.145 0.114 0.048 482 98.8 4.9
9 0.1181 2.91 0.271 0.234 0.053 259 96.5 2.7
10 0.1313 2.76 0.398 0.333 0.058 183 102.8 1.8
Then i merge this fifth data with the other four and get the
stastics like this,
N 1/d^2 Dmin(A) Rmrg Rfull Rcum Av_I SIGMA I/sigma
$$
1 0.0131 8.73 0.072 0.048 0.072 7545 954.4 7.9
2 0.0263 6.17 0.100 0.057 0.085 3417 528.8 6.5
3 0.0394 5.04 0.145 0.072 0.103 2497 543.6 4.6
4 0.0525 4.36 0.158 0.089 0.121 3308 790.6 4.2
5 0.0656 3.90 0.200 0.091 0.138 2374 710.3 3.3
6 0.0788 3.56 0.299 0.128 0.158 1496 663.8 2.3
7 0.0919 3.30 0.462 0.173 0.177 848 644.7 1.3
8 0.1050 3.09 0.577 0.144 0.187 483 414.7 1.2
9 0.1181 2.91 0.720 0.265 0.192 311 358.2 0.9
10 0.1312 2.76 0.392 0.342 0.192 217 122.7 1.8
My question is that after why the SIG_I becomes very large at
different resolution shells merging the five data. Say, at 8.73A,
merging the four low-resolution files give about SIG_I of 125; the
single high-resolution file give 416, but after merging, they give
up to 954, is this normal? or i made something wrong?
Thank you very much in advance!
Fengyun
