TODO

• Increase test coverage.
• pydl.pydlutils.mangle needs more work.
  • Area (solid angle) calculation.
  • Area calculation needs to account for the use_caps attribute.
  • Intersection of caps with other caps.
• Use numpy/scipy Cholesky tools
  • https://trac.sdss.org/browser/repo/sdss/idlutils/trunk/pro/bspline/cholesky_band.pro
  • https://docs.scipy.org/doc/scipy/reference/generated/scipy.linalg.cholesky.html
  • https://docs.scipy.org/doc/numpy/reference/generated/numpy.linalg.cholesky.html
• Update astropy_helpers to v2.0.8.
• Check groupdim, groupsize in djs_reject(). Make sure integer division works.
• Document bspline.