Hello all,
I believe I’m having a similar problem as another user from a few years ago but I cannot resolve the issue. When I use the nD peak picker in my 4D spectrum, it runs for a while but then does not pick any peaks.
When I try to pick peaks manually (ctrl+shift+drag), only sometimes does a peak end up being picked even when I try all the layers I know is close to where the extremum is. If I place a peak and then use S,E (snap to extremum) again, it only sometimes works. I’ve set the noise level high but still see intense enough peaks that I believe should be picked.
Also, I’m using v3.1. I’d appreciate any help!
Thank you very much,
Maia
Hi Maia,
we don’t have a huge number of 4Ds with which to test this. But the peak picking seems to be okay for the 4Ds which I have (though yes, sometimes you have to check a bit that the z1 and z2 axes are in the correct place).
I’m afraid my first suggestion is going to be that you update the program to version 3.3.2.1 which is the latest version. Your version is over a year old by now and it could be that this is an issue we have already fixed.
If you like, you can also send us your spectrum to support@ccpn.ac.uk and we can take a look and see what might be going on.
Vicky
Thank you for your advice Vicky!
I will try updating and picking peaks again. Also, if there are multiple peak extrema at different z2 but the same z1 (and same x and y coordinates), would the peak picker pick all the peaks at the different z2?
Sorry if that’s not very clear; there are many overlapping peaks in the 3D spectrum, but the 4D separates them in the z2.
Thanks,
Maia
Hi Maia,
a brief point on updates: to update from 3.1 to 3.2/3.3 you will need to use a new download from Software Downloads - CCPN, as we changed the python environment when we moved from 3.1 to 3.2.
The peak picking will only pick peaks at the z2 dimension shown. So if you have lots of peaks which are overlapped in x/y/z1, but separated in z2, I would recommend right-clicking on that set of peaks and going to Flip Axes / New SpectrumDisplay with Axes flipped (or use shortcut FA). Then select the axis arrangement that will swap the z2 and y axes. You should then see a vertical strip of the peaks separated along the y axis and should be able to pick them with the normal area peak pick.
I haven’t worked much with 4Ds before, but I would imagine that it could be quite helpful to work with the spectrum being shown in different ways in parallel - if only to be able to work out better in your head what is going on and how the peaks are arranged!
Vicky
Thank you very much Vicky,
That makes a lot of sense and I will give it a try!
Maia