Cube manipulation

Slightly more complex is manipulation and resampling of the data cube itself. The most important utilities available to do this within KAPPA are the collapse, chanmap, ndfcopy, and pluck applications. collapse can produce white-light and passband images and velocity maps by the appropriate selection of statistic. chanmap creates a grid of passbands. ndfcopy can extract a single spectrum (along pixel axes) or arbitrary cube sections , while pluck uses interpolation to extract at arbitrary positions, such as a spectrum at nominated equatorial co-ordinates, or an image at a given wavelength or frequency. Some applications require the spectral axis to be the first or the third axis; permaxes allows shuffling of the pixel axes.

• chanmap
  Creates a channel map from a cube NDF by compressing slices along a nominated axis
• collapse
  Reduces the number of axes in an $N$-dimensional NDF by compressing it along a nominated axis
• compadd
  Reduces the size of an NDF by adding values in rectangular boxes
• compave
  Reduces the size of an NDF by averaging values in rectangular boxes
• compick
  Reduces the size of an NDF by picking equally spaced pixels
• flip
  Reverses an NDF's pixels along a specified dimension
• ndfcopy
  Copies an NDF, or an NDF section, to a new location
• permaxes
  Permutes an NDF's pixel axes
• pixdupe
  Expands an NDF by pixel duplication
• pluck
  Plucks slices from an NDF at arbitrary positions
• regrid
  Applies a geometrical transformation to an NDF
• segment
  Copies polygonal segments from one NDF into another
• slide
  Realigns an NDF using a translation.