Thanks.
I now got the extra column, but it only holds 0’s, which can’t be right. I’d expect monotonically increasing values.
I suppose:
S->data[4][e] = modnorm; /* Model norm at this point */
should only be executed when the for-loop has terminated?
– I just tested it — Nope 
modnorm itself is having a value and is increasing, though, just not written to file.
Probably my error. See if things at line 2649 and ~2680 are now correct for your cumulative sum. There is obviously something I am blind too…
I do not see a new commit right now.
sorry just hit it
So, the values make perfect sense and I got a beautiful L-curve now:
I computed the data norm as:
sum(((prediction - observation) / uncertainty) ** 2)
If both of them would be included as the last two columns of -Efile+n this would be really charming. A really nice bonus would be, if all this would work in combination with -C+n, i.e. in dry-run mode.
Let me know if I can help, now that I got kind of a development environment set up.
What is best for us is if you can submit a commit to the green-modnorm brach with what works well for you some can have a look. Then all is done on GitHub instead of bits and pieces in the forum
Just a reminder. The preferred way to get this done is for you to add to the branch on GitHub.
Hi, is there an update on this one?
I’m very much interested in getting the polynomial coefficients to fit a surface but the commit is still open 
@seisman maybe ?