Thanks, Matt. We initially thought that this was the problem with the Analyst API. Tried version 1.4, 1.5.0, 1.5.1, and now are on 1.5.2. Same problem.
I looked through the mzWiff code and didn't see any type of odd filtering, so thanks for confirming. Karina -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Matthew Chambers Sent: Wednesday, January 19, 2011 4:29 PM To: [email protected] Subject: Re: [spctools-discuss] data points missing after mzwiff conversion to mzXML An infuriating quirk of the WIFF APIs I've used is they return profile data without flanking zero points around the peaks. So if those aren't inserted during conversion, the profile will appear to never reach 0. The fix requires either a hack of inserting a zero point essentially before or after each non-zero point, or a better but harder fix of actually trying to figure out the sample rate at each non-zero data point and extrapolating the x coordinate of the flanking zero point from there. This is the case with both WIFF APIs I've used, I'm not sure if it also applies to the Analyst API mzWiff uses. I seem to recall that at some point I had the latter approach implemented in msconvert, but it's not there now so I probably took it out for performance reasons and meant to return to it later. -Matt On 1/19/2011 3:16 PM, Karina Chmielewski wrote: > We're having issues with missing datapoints after converting wiff files to > mzXML. After conversion > with mzwiff, the "baseline" (0 intensity) datapoints seem to be missing in > the mzXML and a new > "baseline" is created that corresponds to the intensity of the lowest peak in > the original wiff file. > > For example, see screenshot of the wiff from MultiQuant (before conversion). > The lowest peak > intensity is ~50. > > After conversion with mzWiff to mzXML the basline is shifted to ~50 and all > peaks with intensity < > 50 are gone. Any idea what might be causing this? > -- You received this message because you are subscribed to the Google Groups "spctools-discuss" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/spctools-discuss?hl=en. This message contains information which may be confidential and privileged. Unless you are the addressee (or authorized to receive for the addressee), you may not use, copy or disclose to anyone the message or any information contained in the message. If you have received the message in error, please notify the sender immediately by replying to this message or calling (617)649-8600, and delete the original message and any attachments from your electronic files. Thank you for your cooperation. -- You received this message because you are subscribed to the Google Groups "spctools-discuss" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/spctools-discuss?hl=en.
