[R-meta] converting escalc ROM outputs to the log-2 scale
Hi Dr. Wolfgang Thank you for getting back to me. Could you help me understand more on why we square the log(2) in the vi calculation? On Fri, Dec 11, 2020 at 6:37 PM Viechtbauer, Wolfgang (SP) <
wolfgang.viechtbauer at maastrichtuniversity.nl> wrote:
Dear Divya, If y_i ~ N(theta_i, v_i), then for any constant c, c*y_i ~ N(c*theta_i, c^2 * v_i). So, it would be yi_new = yi/log(2) and vi_new = vi/log(2)^2. Best, Wolfgang
-----Original Message----- From: R-sig-meta-analysis [mailto:
r-sig-meta-analysis-bounces at r-project.org]
On Behalf Of Divya Ravichandar Sent: Friday, 11 December, 2020 23:36 To: r-sig-meta-analysis at r-project.org Subject: [R-meta] converting escalc ROM outputs to the log-2 scale Hi all I have a question around changing the scale of *yi *and *vi *exported from *escalc() *function when using *measure=ROM.* Based on the documentation, this function exports *yi *in natural log (ln) scale. --> yi = ln(grp1-mean/grp2-mean) and then the associated vi. I am interested in obtaining the *log-2 fold change. *Is there a way to convert yi & vi from *escalc(measure = ROM,...) *to this scale. Would it
be
reasonable to simply transform the values by converting from log-e ->
log-2
scale by yi_new = yi/log(2) and vi_new = vi/log(2) Thank you -- *Divya Ravichandar* Scientist Second Genome
*Divya Ravichandar* Scientist Second Genome [[alternative HTML version deleted]]