Re: [Psidev-ms-dev] PSI-MSS WG Tuesday call reminder

[Coleman, M. <MK...@st...>]

I¹ve been on vacation, so this is a bit late.  Comments below.

On 6/12/09 10:05 AM, "Matthew Chambers" <mat...@va...>
wrote:
> This is what I was refuting below. Assuming 15 or fewer base10 digits
> are needed, a double precision float is a better representation than
> ASCII in every way except human readability. Do you have examples of
> reference data that uses more than 15 digits in ASCII?

For what it's worth, in greylag, the mass used for O (Oxygen) has 12 decimal
digits to the right of the decimal point.  (This value comes from NIST, and
is meant to be as precise as possible.)  Since peptides/proteins have masses
of at least 1000 Da, this means that at least 16-17 significant digits would
be needed to fully represent these calculations.

One might dispute whether or not this level of precision is useful, but
since you asked, there's an example.

> And unless you can demonstrate that you need more
> than 15 digits of precision in your data, human readability is the only
> reason for ASCII representation.

I would argue that the possibility of writing trivial programs that read
peak data is also a reason, perhaps a more important one.  Having the peaks
encoded does make it a bit harder to jump in and start doing something with
them.

Mike