Re: [Psidev-ms-dev] Unit terms in binaryDataArrays

[Matt C. <mat...@va...>]

When you say state a fixed unit, do you mean in the binaryDataArray 
(i.e. always require a MS_second term) or just implicit? I don't like 
the implicit idea. And I think the vendors should store whatever comes 
off the instrument. Thermo's control software talks in minutes as far as 
I can tell, I don't see a reason to force it to seconds for mzML. It 
might be possible to force the time array to seconds, but it isn't 
possible to force the intensity array to be ion current because some 
instruments measure counts. So intensity arrays should also have units 
specified. The rule mapping should have logic like:
binaryDataArray:
    // m/z array has no unit
    if type is intensity array: MAY have intensity unit type
    else if type is time array: MAY have time unit type
    else if type is wavelength array: MAY have wavelength unit type // 
UV spectra?

These units can't be required, but MIAPE should probably have them.

-Matt


Rune Schjellerup Philosof wrote:
> I think the easiest solution for chromatograms is to state a fixed unit, 
> seconds for instance, and I can not see any drawbacks to this (at least 
> when it comes to chromatograms).
>
> --
> Rune
>
> Matt Chambers wrote:
>   
>> The semantic mapping should allow for a unit term to be specified that 
>> indicates the unit for a given binaryDataArray. This is particularly 
>> important for chromatograms, as it's totally arbitrary which time unit 
>> is chosen for the primary time axis!
>>
>> -Matt
>>