Grep A Pattern From File

Question

[federico.gaiti]

I am trying to use grep to pull out express values.

I run eXpress and I have my .xprs tab separated value file which looks like this:

bundle_id   target_id   length  eff_length  tot_counts  uniq_counts est_counts  eff_counts  ambig_distr_alpha   ambig_distr_beta    fpkm    fpkm_conf_low   fpkm_conf_high  solvable
1   Contig14365 310 106.787904  85  85  85.000000   246.750792  0.000000e+00    0.000000e+00    147.370523  147.370523  147.370523  T
2   Singlet_45262   346 232.432874  109 37  89.933541   133.875234  1.998601e+00    7.198885e-01    71.637085   51.273440   92.000730   T
2   Singlet_68764   236 119.092916  74  2   21.066459   41.746263   6.254955e+00    1.736541e+01    32.750608   0.142967    65.358248   T
3   Contig1270  736 500.694431  50  0   0.125252    0.184116    1.000000e+00    1.000000e+00    0.046316    0.000000    0.759071    F
3   Contig1271  851 628.717767  57  9   43.657462   59.092492   4.701649e-01    1.810055e-01    12.856315   4.051524    21.661106   T
3   Singlet_69558   790 555.880836  50  0   15.217286   21.626318   1.000000e+00    1.000000e+00    5.068381    0.000000    12.670313   F

I want to get non-codingRNA-specific express values so I thought to use:

grep -f <list of ncRNAs contigs> <express file>

I made a file with ncRNAs contigs IDs which looks like this:

Singlet_51268
Singlet_63946
Singlet_70630
Singlet_72272
Singlet_60543
Contig11105
Singlet_18043
Singlet_64779
Singlet_50335
Singlet_39678
Singlet_21655
Singlet_5438
Singlet_6400
Contig4197
Singlet_17193
Singlet_55710
Singlet_70948
Singlet_25172
Singlet_65515
Singlet_30239
Singlet_54617
Singlet_11188
Contig14540

Since my ncRNAs are 577, I expect to end up with a .xprs file with 577 rows but I ended up with a .xprs file of 701 Contigs.

So I have 124 Contigs that do not correspond to my ncRNAs.

How could I pull out ncRNAs-specific values? I tried playing around with grep but I can't fix it.

Any suggestions?

THanks

Answer 1

[rbagnall]

I think you need to add -w (grep word).

Without this, grepping Singlet_51268 will also pull out Singlet_512681, Singlet_512682, Singlet_512683 etc..

try:

grep -w -f <list of ncRNAs contigs> <express file>

[federico.gaiti]

it worked perfectly. Thankls for the right and fast answer!

[lh3]

Please use grep -wFf <list>. It will be much faster given a long list.