iolite v4 now comes with a tool that helps you identify issues with your selections. Sometimes, errant selections can cause a DRS not to run properly, or result in many error messages. It can be difficult to find the offending selections sometimes too. So we’ve created a tool that checks for common issues with selections. Depending on the severity of the issue, iolite may halt the progress of a DRS or processing template to give you time to fix the issues, or iolite may just warn you that there is a potential issue.
Checking your selections
In the Selection Browser, there are two new buttons. One has an exclamation mark in a triangle, and you can click this button to run a check on your selections. If there are any issues with your selections, the color of the button will change: to orange if there are just warnings; or, to red if there are errors. There are also little error icons added beside any selection that has an issue in the list of selections. Again, if the icon is red, it is an error, and yellow if it is just a warning.
Also, now if you right-click on a selection in the list, an option to go to that selection in the Time Series View will appear. This can make it easier to find an selection with some sort of issue, and go straight to it to better understand what is going wrong.
What are the errors and warnings iolite is telling me about?
At the moment, there is just one situation that will be reported as an “Error”: where a selection does not overlap any measured data.
This can happen for a variety of reasons. For example, I was recently sent a dataset where an experiment was set up so that each spot ablation was treated as a separate sample by the mass spectrometer. This meant that each sample was in its own file. Normally, this is not a problem, however in this case for some reason the mass spec failed to measure a sample, so there wasn’t a file for it and therefore no data were imported into iolite during this sample’s ablation. But the laser log file still recorded the ablation, and so when the user created selections from the laser log file, there was a selection for the missing data. The missing data was for a reference material, and so the DRS the user was trying to run after creating the selections was reporting an error and wouldn’t continue. The missing sample was one of hundreds in the session, and so it was very hard to find. With the new Selection Checker, this selection would now be highlighted as having an error. If you were to click on the selection in the Selection Browser, a message at the top of the window tells you why iolite thought it was an error. Deleting this selection allows the DRS to run to completion without any errors.
There are (currently) two sitations that iolite will flag as warnings (we may add others in the future):
-1 Two selections within the same group that overlap in time; or
-2 A selection contains very few datapoints (< 5)
The first is just a warning in case you’ve accidentally added the same selections twice (or more times). This can be very hard to distinguish visually if they have the same mean/2SE etc. It is just a warning because there may be valid reasons for overlapping selections. However, you should be aware that overlapping selections will mean that the same datapoints are included in more than one mean, reported as the average for the selection on export.
Similarly, very short selections may be valid because you’re looking at a very small feature. However, typically you’ll want more than 5 points to calculate a mean etc, which is why iolite will flag it as a warning so that you can review it. Also very short selections can be hard to see and delete when looking for errant selections.
What is the other button for?
The other new button in the Selection Browser has a filter (funnel) icon on it. If you click this button to toggle it on, only selections with a warning or error will appear in the list of selections. This makes it even easier to find that one selection with an error in hundreds of selections. Click it again to turn the filter off.
Automatically checking for errors
iolite will now automatically check for selection errors when you click Crunch on a DRS, or when a DRS runs as part of a processing template. If there are any errors, the DRS/template will stop and tell you there is an issue so that you can fix it before continuing. Selection warnings will not stop the DRS/template from running, and it will continue but still report the warnings to the Messages View.
If you would like to turn this behaviour off, you can click on the wrench icon in the DRS View, and uncheck the “Check selections before crunching” option. iolite will not perform any check for errors or warnings when you click Crunch, and the DRS will not stop in the case of errors.
If you have any questions or suggestions for this feature, you can join the discussion here.
