WIP: NC data model and more

[kmuehlbauer]

This proposes the use of a netCDF file for handling data.

As netCDF is a widely used standard and can be read by almost every processing/visualisation software it is proposed to use this as a data model for handling radar data.

Implemented features (so far):

• Create netcdf-file tmpfile.nc with data structure which should comply to CF-standard (as much as possible)
• Add first and last data file to nc-file
• Add missing data files, when they are about to be inspected
• Line Plot as DockWidget, showing timely evolution of one pixel
• activate chunking for better access for different slices (one time-step/whole-domain, multiple time-steps/single-pixel )
• Add automatic zoom into data for LinePlot
• Cursor and SelectionCursor in GL_Canvas
• Cursors in LineCanvas + doubleclick sets current time
• use in-memory netcdf-file for relatively small datasets
• Save to named netcdc-file

[kmuehlbauer]

• Chunking working for 900, 900 up to 288 time frames (1day, 5min steps)
• Added Line plot which shows time evolution of one pixel

[kmuehlbauer]

• added cursors and selection cursors for better visualisation which coordinate is shown in time graph

[kmuehlbauer]

• added cursors in LineCanvas, showing lower and upper bound of selected time range and current timestep

[kmuehlbauer]

This is now going into consolidation phase. @heistermann you might play with this a bit, I'll try to clean everything up.

[kmuehlbauer]

started to do some class shaping inside glcanvas.py

[kmuehlbauer]

fixed DXCanvas:

• works now with netcdf file object
• subclassed from GlCanvas, which has all methods for interaction (mouse/cursor)
• PolarTransform imap function now converts directly to (degree, range) instead of (radians, range)