pix2xxx, ang2xxx, vec2xxx, nest2ring, ring2nest
name (dim.) | type | in/out | description |
---|---|---|---|
nside | scalar integer | IN | Nside parameter for the HEALPix map. |
ipnest(n) | vector integer | -- | pixel identification number in NESTED scheme over the range {0,Npix - 1}. |
ipring(n) | vector integer | -- | pixel identification number in RING scheme over the range {0,Npix - 1}. |
theta(n) | vector double | -- | colatitude in radians measured southward from
north pole in {0,![]() |
phi(n) | vector double | -- | longitude in radians, measured eastward in {0,2![]() |
vector(n,3) | array double | -- | three dimensional cartesian position vector (x, y, z). The north pole is (0, 0, 1). An output vector is normalised to unity. The coordinates are ordered as follows x(0),..., x(n - 1), y(0),..., y(n - 1), z(0),..., z(n - 1) |
vertex(n,3,4) | array double | optional OUT | three dimensional cartesian position vector (x, y, z). Contains the location of the four vertices (=corners) of a pixel in the order North, West, South, East. The coordinates are ordered as follows xN(0),..., xN(n - 1), yN(0),..., yN(n - 1), zN(0),..., zN(n - 1), xW(0),..., xW(n - 1), yW(0),..., yW(n - 1),I>zW(0),..., zW(n - 1), and so on with South and East vertices |
ROUTINES:
pix2ang_ring, nside, ipring, theta, phi
renders theta and phi coordinates of the nominal pixel center given the pixel number ipring and a map resolution parameter nside. |
renders cartesian vector coordinates of the nominal pixel center given the pixel number ipring and a map resolution parameter nside. Optionally returns the location of the 4 vertices for the pixel(s) under consideration |
renders the pixel number ipring for a pixel which, given the map resolution parameter nside, contains the point on the sphere at angular coordinates theta and phi. |
renders the pixel number ipring for a pixel which, given the map resolution parameter nside, contains the point on the sphere at cartesian coordinates vector. |
renders theta and phi coordinates of the nominal pixel center given the pixel number ipnest and a map resolution parameter nside. |
renders cartesian vector coordinates of the nominal pixel center given the pixel number ipnest and a map resolution parameter nside. Optionally returns the location of the 4 vertices for the pixel(s) under consideration |
renders the pixel number ipnest for a pixel which, given the map resolution parameter nside, contains the point on the sphere at angular coordinates theta and phi. |
renders the pixel number ipnest for a pixel which, given the map resolution parameter nside, contains the point on the sphere at cartesian coordinates vector. |
performs conversion from NESTED to RING pixel number. |
performs conversion from RING to NESTED pixel number. |
pix2ang_ring, 256, [17,1000], theta, phi | |
print,theta,phi |
returns
0.0095683558
2.8797933
position of 2 pixels 17 and 1000 in the RING scheme with parameter 256.
Eric Hivon 2003-02-07