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Messages - uwe.geppert

2
XCMS / Re: help interpreting result
I need help in the Interpretation of XCMS-Results, too.
For my analysis it was not possible to use the same amount of plant tissue in each sample.
Does XCMS compare absolute or relative amounts of substances?
3
XCMS / Re: Centwave optimal parameters
Addendum:

I used MSConvert to create centroid data from the Thermo raw data. Let's see what happens with "ppm=5" ...

Unfortunately no peaks have been found.

Please help!

Now I'm trying: xset<-xcmsSet(steps=1,profmethod="bin") ...
4
XCMS / Re: Centwave optimal parameters
Hello,

i am writing my master thesis in ecology and try to analyse FTICR-MS data.
Since I never analysed statistically LC/MS data before and I am qite new to R I would be very thankful if anyone can provide me with the R code to determine the optimal parameters.
Is Centwave even the right method? What about MassSpecWavelet?

Many thanks and kind regards,
Uwe

P.S.: I used LTQ-FT (Thermo Fisher) and converted the Xcalibur raw files with Xcalibur to net.CDF