v0.18.0

Virtual records

A file may leave records out: sparse records. Variable.virtual_records is one boolean per record, True for the records the file doesn't store.

• It is read from the file, settable, and add_variable(virtual_records=...) takes it. A loaded sparse file stays sparse when saved.
• Checked against NASA's CDF library 3.9.2: the same records are virtual, and cdfvalidate accepts the files.
• Saving refuses a virtual last record. NASA's library can't read the records after the last one a file stores.
• set_values stores every record, and warns when the variable had virtual records. Their new values were silently not saved.

Fixes

• Attributes of type CDF_BYTE can be created. add_attribute and set_values raised "Unsupported CDF type" (#130).
• Attribute.set_values([], []) raised an error instead of emptying the attribute (#130).

CDFpp Explorer

• Particle distributions and other multi-dimensional variables plot by summing, averaging or slicing their dimensions.
• The y axis can be set to linear or log, and tiny or huge values get readable ticks.
• Spectrograms pan and zoom 5 to 8 times faster.
• Plot time axes are in UTC, and say so. They showed the viewer's timezone.