Hi Hiroshi,
regarding the coefficient of variation (CV%) shown by the MS-DIAL normalization report.
I have been manually calculating the QCs across samples and QCs, for some internal standards,
but I do not manage to reproduce exactly the same values.
in MS-DIAL, are the CV% calculated based on the log transformed values? (as the report shows the log scale)
I tried both with and without log transforming. When I use the log values, I use the following formula:
= SQRT (10^(LN(10)*STDEV^2)-1)
as discussed here: 10.15406/mojpb.2017.06.00200
I attach the CV% calculated on the log values (for QCs and Samples), and the corresponding ones from MS-DIAL (in red)
(Note: they are not expressed as %, but as fraction, i.e. CV 0.15 = 15%)
Thank you!
Stefano
Thanks Stefano,
the CV value is simply calculated by the original, i.e. non-transformed values although the Y-scale is finally visualized by log-transformed value. I will prepare both CV values into the figure at next update.
Thanks,
Hiroshi