LabVIEW
Confusing Zoom in XY-Graph
Hello,
recently I wanted to inspect the linearity of data by zooming in into the according XY-graph and got confused, as they where very far from linear according to the graph. Rechecking the data numerically I found that the nonlinearity was in the graph and not in the data, i.e. somehow in the internal representation of the displayed data (rounding issues?).
The same issue comes up when you want to read out a precise interpolation value by zooming into the graph: The interpolation line (=connecting line in the graph) disappears eventually from your zoom window and, if you then pan up and down, displays something else than the interpolation between the two data points.
In the hope that such cases only rarely happen - or that you have warned your users/clients.
Herbert
P.S.: Same in LV 2019 and since ?????
We had discussions about certain distortions when zooming probably 20+ years ago, so this has been around for ages. Curiously, if you zoom in even more, it sometimes becomes linear again...
Obviously, the underlying code takes some shortcuts. graphs need to be highly optimized for speed, because you don't want and xy graph with 1M points hog the UI thread for minutes. 😉
Hard to tell what's going on...
