Assess number of Signatures in Somatic signatures
0
0
Entering edit mode
Asma rabe ▴ 290
@asma-rabe-4697
Last seen 6.8 years ago
Japan

 

Hi ,

I have matrix of mutations count as follows

               T1     T2  T3   T4  …………….. T100

CA A.A     1      0    2    1  …….

CA A.C     1      2      2      1   ….. 

CA A.G     1     0      0      0     ….

CA A.T     5      0      0      0   ….

CA C.A     10      0      1      1  …..

..

...

when i tried finding the best number of signatures  based on RSS and explained variance plots, it was 5 ,when i normalized the counts by the total number of events observed in each sample, i.e. dividing by the column sums, the best number of signatures became 10, Any idea??

 

Thank you very much.

 

somaticsignatures • 1.5k views
ADD COMMENT
0
Entering edit mode

Can you please have a look at http://www.bioconductor.org/help/support/posting-guide/ again and provide a reproducible example? The motif matrix you show in your question has data for 4 samples, and hence it is impossible to decompose this into more than 4 signatures, while you state that you have 5.

ADD REPLY
0
Entering edit mode

Hi Julian,

Thanks for reply,the matrix above is just an example. the original matrix which i am using have ~100 samples.

ADD REPLY
0
Entering edit mode

Any idea why the number of signatures that best describes the data is different after normalizing by colSum??

ADD REPLY
0
Entering edit mode

Please note that you haven't yet provided a concrete example with details. Without this, addressing the issue will hardly be possible and pushing for an answer also not be very helpful.

ADD REPLY

Login before adding your answer.

Traffic: 740 users visited in the last hour
Help About
FAQ
Access RSS
API
Stats

Use of this site constitutes acceptance of our User Agreement and Privacy Policy.

Powered by the version 2.3.6