Manipulate data for a single group

kai2

Hi all,

this has probably come up before but i can't find anything and I also forget my Python so quickly if I'm not using it so i'll ask here:
I'm measuring concentrations on e.g. 610 using 50 microns, and then a sample using 100 microns. Where is the best place to perform a mathematical operation (e.g., 610 = 610 * 100² / 50²) on all channels in a single group but not all data as a whole? data.selectionGroup('G_NIST610') is not the way to go because i want to change all the raw data not just the selections. If I start with the channel data d = data.timeSeries('U238').data() then this works on all groups. How do I pick data from just one group? Can this somehow be done in the Channel Calculator app??

And another similar thing: I want to study the effect of an interference on one isotope in the std group. So I would like to add a number to a specific channel only for the 610 selections.

Any help greatly appreciated!

Cheers

Bence

Hi @kai2

At the moment, there isn't a super straightforward way of doing this. The way that I would do it via the python interface is to create a copy of the data of the channel you want to edit, and then adjust the data for the indices representing the selections in that group, and then set the channel data to the edited data. Something like this:

ts = data.timeSeries('Pb208')

sg = data.selectionGroup('G_NIST610')

d = ts.data()

for sel in sg.selections():
    d_edit = ts.dataForSelection(sel)
    d_edit *= 2        #Add your calculation here
    d[ts.selectionIndices(sel)] = d_edit

data.emitDataChanged()

The line d[ts.selectionIndices(sel)] = d_edit updates the data array of the channel that you extracted with d = ts.data() but only between the start and end indices of the selection.

Please let me know if that doesn't do what you want it to 🙂

Kind regards,
Bence

kai2

yes that would work for me many thanks! I was looking through the API documentation yesterday to see what functions there are to help. 'data.emitDataChanged' for example is there but not documented as far as i can see. Do you have a more in-depth documentation of your API?

Bence

kai2 Do you have a more in-depth documentation of your API?

It's on our list for the next release of iolite (in about a month's time). There's been quite a bit of change recently, so it's a little overdue.

I'm writing a new system for making sure it's updated with each new release, rather than the manual approach we have now. Once that's in place, it should be a bit more reliable. Sorry about that!

Bence

BTW, data.emitDataChanged() tells iolite that the data have changed, and so it will cause iolite to update all of its user interface.

Kind regards,
Bence

Bence

Just updating this: the python API has now been updated for v4.10.1.

Please let us know if you spot any errors, or if you have any questions.