The Peak Inspector and Table provide excellent access to information about each peak, but often there is nothing better than actually looking at them. But how do you know you've seen them all. If you try to visually scan across peaks displayed in a spectrum it's hard to be systematic and check every peak. NMRViewJ provides a very powerful and relatively rapid method for systematically examining peaks. One or more windows can be set to have their spectral display region adjusted whenever the choice of peak displayed in the Peak Inspector changes. By stepping from the first to the last peak in the Peak Inspector, and observing the corresponding display in the spectra you can be sure you've examined each and every peak.
The controlled windows have their display region changed so that they are centered on the chemical shift of the corresponding peak. Windows are set up to be controlled by setting the Show Mode in the Peak tab of the Spectrum Attributes panel. When setting this up it is a good idea to first set the Show Mode attribute to the mode. With this setting, the width of the display region will be set to a multiple of five times that of the width of the peak's bounding box. Step through a few peaks with the Peak Inspector till you find a peak that has a fairly typical intensity for the particular peak list. Now change the Show Mode to the mode. With this setting, the display will center on the peak position, but the display regions width will remain constant. Now, as you step through the individual peaks in the list their relative widths will be visually obvious.
This facility for peak examination is very useful in the analysis of biomolecular NMR spectra. While it's possible to automate the elimination of artifactual peaks as described above an interactive method can be valuable. Actually looking at the shape and distribution of peaks can be very important for discovering artifacts in spectra that may lead to insights into new NMR experiments, and for recognizing extra peaks or missing peaks that indicate conformational dynamics, multiple species in solution, or ligand binding effects.
It's useful to remember that multiple spectra can be updated simultaneously with this method. In this way you can systematically compare peaks from spectra collected under different conditions, for example comparing spectra of proteins collected in the presence of different ligands or for comparing wild type and mutant forms of proteins. In this case you'll often set the Peak Inspector to use a peak list from a dataset collected under the reference condition (wild type protein, zero ligand, etc.) Using this method for quickly examining peaks has been also very useful for cleaning up peak lists prior to using the lists in relaxation analysis or assignment using the RunAbout tool described below. While RunAbout provides its own systematic way of visualizing multiple datasets simultaneously, it's a good idea to use Systematic Peak Analysis on the refernce list (typically the HSQC or HNCO experiment before starting with RunAbout).
The default spectrum key bindings are set up so that it is easy to step through spectra. After clicking in the target spectrum window, you can use the Page Up and Page Down keys to move forward and backward through peak list.