NDF History

During a spring clean of directories to free some space (what d' y'mean you don't?), most of us will have encountered data files whose purpose and worth are long forgotten. We're reluctant to remove them in case they contain irreplaceable data. Some people are very good and make copious notes... Even then the result of a casual experiment might not be recorded. For those who are lazy, such files can be a frequent dilemma. Even a quick look at a plot of the data is often of little assistance. As you've probably surmised, the NDF offers a solution.

Within an NDF you may record history information. This is usually a chronicle of the processing stages used to form the NDF, including the parameter values of the applications invoked; but it may also include commentary you provide, for example, the rationale for doing certain operations.

History is associated with individual NDFs; it is not some global attribute of a data-processing session. An NDF has a history update mode, which remains with the NDF and any descendant NDF, until the update mode is altered or the history erased. By default, the update mode is "Disabled", meaning that no history recording occurs. To permit history recording you must first switch it on, selecting from three update modes--"Quiet", "Normal", and "Verbose"--which give increasingly more detailed information.