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Messages - Xinrui

1
CAMERA / Re: Isotopes identification
Hi,

Thank you so much for your response. isotopeMatrix is what I need.

But what do intmin and intmax mean? For example, in

Quote
isotopeMatrix <- matrix(NA, 8, 4);
colnames(isotopeMatrix) <- c("mzmin", "mzmax", "intmin", "intmax")
 
  isotopeMatrix[1, ] <- c(1.000, 1.0040, 1.0, 150)
  isotopeMatrix[2, ] <- c(0.997, 1.0040, 0.01, 200)

isotopeMatrix[2, 4] = 200.

Does it mean that the (int[M] / int[M+2]) or (int[M+1] / int[M+2]) must be smaller than 200?

Many thanks.

Cheers,
Xinrui
2
CAMERA / Isotopes identification
Hi,

I have a question about the findIsotopic function in CAMERA.

For two coeluting lipids differing by one double bond, the masses differ by 2. By using findIsotpic function, the first lipid is identified as M+. And the second lipid is sometimes identified as M+2, even when its intensity is much higher than M+1.

How can I tell findIsotopic function that these are two different lipids? Is there any way considering intensity during isotopes identification?

Similar problem is also mentioned in the last 3 replies in http://metabolomics-forum.com/viewtopic ... 7a85e#p223 .

Thanks.

Xinrui