Module cube_io 

FITS spectral cube reading and writing with per-channel beam support.

Supports 3D cubes (NAXIS=3: freq×dec×ra) and 4D cubes (NAXIS=4: stokes×freq×dec×ra). Per-channel beams are read from, in priority order:

1. CASA BEAMS binary-table extension (CASAMBM=T in header)
2. Co-located beamlog text file: {dir}/beamlog.{stem}.txt
3. Single BMAJ/BMIN/BPA from the primary header (broadcast to all channels)

Structs

CubeMeta

Metadata for a FITS spectral cube (3D or 4D).

CubeWriter

A streaming writer that holds an initialised output cube open for the lifetime of a processing run, so channels can be written one at a time without the per-call file open/close overhead of write_channel.

Enums

CubeError

CubeMode

Mode for common-beam determination.

Functions

init_output_cube

Initialise an output cube by copying the input, then updating the beam headers.

read_beamlog

Read per-channel beams from a plain-text beamlog.

read_channel

Read a single frequency channel from a cube into a 2D array (ny × nx).

read_cube_meta

Read metadata (shape, pixel scale, per-channel beams) from a FITS cube.

write_beamlog

Write per-channel beams to a plain-text beamlog.

write_channel

Write a single frequency channel plane back into an existing FITS cube.