MAP --> inspector --> export options

ddsavard

Hi guys!
Instead of recalculate it with EXCEL, is it possible to export 2SD instead of 2SE in the Data Table in the imaging menu after a selection of areas using the Inspector tool (region of interest, with inspector = stats)?
Thanks
Dany

Bence

Hi Dany,

is it possible to export 2SD instead of 2SE in the Data Table in the imaging menu after a selection of areas using the Inspector tool

Certainly. We'll add it in an upcoming release.

Just to be clear, you'd like the option of iolite reporting the 2SD in the Imaging Data Table? We could add a checkbox after the Show Profiles checkbox to allow you to choose between 2SD and 2SE.

Cheers,
Bence

Geonostalgia

Bence,
Just to be clear, the 2SD or 2SE of a region of interest in the imaging data table is the average of the 2SD or 2SE of all the constituent points of that ROI, correct?

Bence

Hi @Geonostalgia,

No, the uncertainty value is the uncertainty of all measurements with the ROI, rather than the average uncertainty of the points within the ROI.

I hope that makes sense? If not, please let me know.

Kind regards,
Bence

Geonostalgia

Bence,
Thanks for the reply - sorry for being thick, but I think I must be confused about something fundamental. For imaging, I thought points = pixels = duty cycles of the mass spec = measurements. I must be wrong somewhere in that chain.

In the example I am thinking of, I have an ROI of 400 points. I have used the "subdivide" feature to break this down into 400 ROIs of 1 point each, which all together should correspond to the original. However, the average and 2SD of the original ROI are slightly off from the ones I calculated from all 400 1-point ROIs. Where am I going wrong in my equivalencies?

Joe

Geonostalgia

The average and 2SD of the 400 point ROI in iolite will use whichever stats method you have selected which probably includes outlier rejection. I wonder whether that is the source of the discrepancy?

The "points" for an ROI is how many time-slices of original data it maps back to. This does not necessarily map to pixels because each point of data might map to multiple pixels (e.g., cell space may represent a single data point with a circle represented by N pixels and some of those pixels might even be averaged with other overlapping pixels). There are also image filters that can manipulate the image resolution making pixels not equal to points.

All the best,

Geonostalgia

Joe

Thank your for your reply, I think this is becoming clearer to me now. I was aware of outlier rejection for baselines in the Stats section of preferences, but failed to recognize that used for normal stats calculations just below it - when I include 3SD outlier rejection in my own single-point SD calculations now line up.

Your explanations of points vs pixels makes sense too. Just to confirm my understanding, outside of cell space, the conversion of a single point into multiple pixels could be seen when different forms of alignment (start, center, justify, etc.) stretch points at different locations into multiple pixels, correct?

Thanks again!