Re: Fwd: WGCNA: labeledHeatmap and verboseScatterplot correlations and p-values are not the same

Peter Langfelder <[email protected]>
Newsgroups gmane.science.biology.informatics.conductor
Message-ID <CA+hbrhUHFe9_z1s9i-cfmN6MRFc7TL_+5+wuAmn-jYqgdynxow@mail.gmail.com>
Hi Sindre,

please see inline.

On Sat, Aug 9, 2014 at 9:47 AM, Sindre Lee <sindre.lee-/[email protected]> wrote:
> Thank you! I understand now, its actually well described on the webpage and
> in the documentation, I should have used more time reading before posting.
>
> If you have the time, I actually have a few more questions:
>
> 1. Why is the module size set at min. 30? What will the implications be if
> larger/smaller?

I feel that 30 is a good compromise between robust large modules and
possibly informative but not as robust small modules. You can
certainly adjust the minimum size, although I rarely find modules
below 30 genes interesting. The implication is very simple - smaller
minimum module size will lead to more modules, but whether this
provides more biological information or just more noise is highly
situation-dependent.

>
> 2. Is it always better to use the step-by-step network construction and
> module detection?

The step-by-step gives you more options to tweak the procedure or
insert your custom code between the steps. Otherwise they are (nearly)
identical. I say nearly because the blockwise... functions include an
extra step of removing peripheral genes from modules.



> Let me give you some details of my design so you
> understand why I ask. I have two time points, from the same persons, before
> and after an intervention. My immediate idea was to run WGCNA on the time
> point 1, relating it to body weight. Then I run WGCNA on time point 2,
> seeing if the same modules pops up. Finally, I run WGCNA on the log-ratio (
> time point 2- time point 1 ) against log-ratio of body weight. If one or
> more modules shows up in all three runs, they will be prioritised. Now, if I
> only use the one-step approach, no modules show up in all three comparisons,
> while using step-by-step looks more promising. However, if I mix the
> results, using one-step on time point 1, but step-by-step on time point 2,
> its even more interesting.


If you want to see modules that pop up in all 3 data sets, use the
consensus module approach. But it's not clear to me that looking for
modules in data set 1, data set 2, and the log-ratio of the two makes
sense. You could get consensus modules across sets 1 and 2, and then
see if the log-ratio of interesting modules is still associated with
the log-ratio of body weight.

Peter

_______________________________________________
Bioconductor mailing list
[email protected]
https://stat.ethz.ch/mailman/listinfo/bioconductor
Search the archives: http://news.gmane.org/gmane.science.biology.informatics.conductor
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.