208Pb correction

MaxD

Hi there,
I am struggling with running the 208 Pb correction (using iolite4 v4.3.7). I tested it for different projects and I get to run 204, 207, and Andersen but not the 208 correction.
Relevant Input channels are Pb204,Pb206,Pb207,Pb208,Th232,U238 and intermediate channels needed for the correction (e.g. the DC ones and C86 and C76) are also created but no Output channels with (208Pb-corr) values, I also cannot see the 208 correction ellipse in VizualAge. There is no error message, when I press calculate (and only select 208) nothing happens (cannot open the options for 208 correction as well).
If you have any ideas what the issue might be I would be very happy, I can also share the project or other parameters if that would help.
Cheers,
Max

Joe

MaxD

I think I see a couple of issues with the code, but it would be helpful if you could also post what python errors are being reported (either in the messages view or in the python console) and also share an example dataset with the iolite support email. A new version of iolite will be released shortly and I'll get this patched for then.

All the best,

MaxD

Hi Joe,
thanks for the reply!
the pyhton error is the following:

calculate_208Pb_correction
Guess age was a string...
:421: RuntimeWarning: invalid value encountered in less
:423: RuntimeWarning: invalid value encountered in less
Traceback (most recent call last):
File ":/vizualage.py", line 433, in calculate_208Pb
TypeError: unsupported operand type(s) for /: 'float' and 'TimeSeriesDataPyInterface'

I also had a look in the code and what I found to be a bit odd is the line 433 saying 's76 = np.copy' where I think it probably misses a variable for the numpy function.
Cheers,
Max

Joe

MaxD

Thanks, Max!

Yes, I also noticed that... strange as that would clearly not work. Should be fixed up for the next release as well as the issue with the options.

All the best,

Romain

Hi there,

I have a similar problem to Max with the 208Pb correction, although I am on version 4.3.9.

Intermediate channels (e.g., C76, C86) are created but it does not got further that this.

Here is the Python consol error message:

options_208Pb()
Accepted
calculate_208Pb_correction
Guess age was a string...
:421: RuntimeWarning: invalid value encountered in less
:423: RuntimeWarning: invalid value encountered in less
Traceback (most recent call last):
File ":/vizualage.py", line 433, in calculate_208Pb
RuntimeError: std::runtime_error: [DataManager::timeSeries] no matches for Pb207/Pb206

Did you guys find a fix for this?

Thanks
Romain

Joe

Hi Romain,

I think if you're running the U-Pb geochronology DRS it does not create the Pb207/Pb206 channel that the 208 correction is looking for. UcomPbine does, which is what I was testing it with. I'll add the raw 7/6 ratio to the normal U-Pb DRS. In the meantime, you could probably make it work with a one-liner in the python console:

data.createTimeSeries('Pb207/Pb206', data.Intermediate, None, data.timeSeries('DC Pb207/Pb206').data())

which just copies the DC Pb207/Pb206 data into a channel of the name the calculation is looking for.

All the best,

Romain

Thanks Joe, it does work if I create the Pb207/Pb206 channel beforehand indeed.

Cheers
Romain