GNOME Bugzilla – Bug 624273
"Contour plot": desired feature: Ability to define upper and lower borders of the categories (classes) manually
Last modified: 2010-09-23 14:51:32 UTC
Created attachment 165828 [details] screenshot: desired feature "preset breaks / (Vorbestimmte Unterbrechungen) " for the contour plot When I used the histogram in the statistics submenu last time (statistics -> descriptive statistics -> frequency tables -> histogram) I found a usefull feature "preset breaks" ("Vorbestimmte Unterbrechungen") (see screenshot in attachement). This feature might be very usefull for the contour plot, too if you need categories of different sizes. In my case I need a hight resolution (tight categories) for lower values and a low resolution (wide categories) for higher values in the same contour plot.
How do you enter the data? As a matrix, or as a series of (x,y,z) coordinates?
Don't care, I looked into the sample you attached to previous bug (#623887). Interesting idea, should be not that difficult to implement, and might also be useful for XYZSurface.
Yes this would be useful for XYZ-surface, too. In this case the surface of the XYZSurface plot would be coloured and we need an additional legend for the colour categories. Normally the colour categories represent the same "Z"-Value as the surface plot itself. So usually there is no additional information in the colour of the surface but the "Z"-Values are often easier to read by the colours in every viewing angle of the surface plot. But in my case it would be even more useful if I had the possibility to show another "Z"-Value by the colour categories. (More than one "Z"-Value you get when you measure two different properties for the same x and y values or if you use different functions for calculating the "Z"-value by the same x and y values) Therefore we would need an additional "Pseudo 3D axis" for XYZSurface and this "Pseudo 3D axis" needs its own data range for the "Z"-Value and its own data range for the "preset breaks" ("Vorbestimmte Unterbrechungen") and its own "Title" that we know what is represented by the legend. This functionalitiy would be pretty cool but I think this will be a lot of work for the XYZ-Surface plot. I think it is much easier to add the "preset breaks" ("Vorbestimmte Unterbrechungen") for the XYZContour plot first.
Things cannot work exactly as for histograms. xyz plots use vertices instead of intervals. Each data is assigned to the nearest vertex. There might be some border effects when vertices are not equally spaced.
This problem has been fixed in our software repository. The fix will go into the next software release. Thank you for your bug report.