A set of Julia functions that implement the Healpix spherical projection.
The purpose of this package is to implement a Julia-only library, instead of providing bindings to the original implementation of the C/C++/Fortran Healpix library. This should make the package easier to port to those architecture which are not supported by the original implementation (e.g., Windows).
Of course, this mean that implementing new features is generally not trivial, as one has to re-implement the algorithm instead of just figuring out how to bind some C/C++/Fortran function.
From the Julia REPL, run
import Pkg Pkg.add("Healpix.jl")
Here are some code snippets that show how to use
Healpix.jl. It is
interesting to have a look at
Refer to the documentation for more examples.
Dealing with resolutions
The resolution of a Healpix map is uniquely determined by the
parameter. Healpix.jl precalculates a number of values from
save time during computations; such values are saved in a
import Healpix res = Healpix.Resolution(256) print("The pixel index is $(Healpix.ang2pixNest(res, 0.1, 0.2))\n")
Reading a map from a FITS file
This snippet loads a map named
planck_70GHz.fits into an array of
64-bit floating-point numbers:
import Healpix m = Healpix.readMapFromFITS("planck_70GHz.fits", 1, Float64) print("average: $(mean(m.pixels))\n")
Healpix.jl is released under the GPL license. Versions before 2.3.0 were released under a MIT license, but this was considered incompatible with the way the code has been written (#15).