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mef3io 1.5.1

Released 2026-10-21.

New

  • Reader.block_envelope(channel, t0=None, t1=None): the minimum and maximum of every data block in a window, with each block's start and end time, read from the block index alone.
  • No signal is decoded, and segments outside the window are skipped, so a viewer can draw a whole day as an envelope for the cost of reading the small index files (about 2% of the data).
  • Returns NumPy arrays (start_uutc, end_uutc, min, max), scaled like read(). A block whose writer left its extremes unset gives NaN; gaps are absent rows.
  • The resolution is the block length: mef3io writes 10-second blocks by default (1-second blocks at 5 kHz and above).
  • Python and C++ (Reader::block_envelope); not yet in MATLAB.
  • The legacy-compatible MefReader has it too (MefReader.block_envelope(channel, t_stamp1, t_stamp2)).

Upgrading

Nothing to change: 1.5.1 only adds block_envelope.