rotate_alm*
This routine transform the scalar (and tensor)
coefficients to
emulate the effect of an arbitrary rotation of the underlying map. The rotation is done
directly on the
using the Wigner rotation matrices, computed by
recursion.
To rotate the
for
the number of
operations scales like
.
Location in HEALPix directory tree: src/f90/mod/alm_tools.F90
FORMAT
ARGUMENTS
name & dimensionality |
kind |
in/out |
description |
|
|
|
|
nlmax |
I4B |
IN |
maximum value for the
. |
alm_TGC(1:p,0:nlmax,0:nlmax) |
SPC/ DPC |
INOUT |
complex
values
before and after rotation of the coordinate system.
The first index here runs from 1:1 for
temperature only, and 1:3 for polarisation. In the latter
case, 1=T, 2=E, 3=B. |
psi |
DP |
IN |
first rotation: angle about the z-axis.
All angles are in radians and should lie in [-2,2], the rotations are
active and the referential system is assumed to be right handed, the routine
coordsys2euler_zyz can be used to generate
the Euler angles
for rotation between standard astronomical coordinate
systems; |
theta |
DP |
IN |
second rotation: angle about the original
(unrotated) y-axis; |
phi |
DP |
IN |
third rotation: angle about the original (unrotated) z-axis; |
EXAMPLE:
use alm_tools, only: rotate_alm
...
call rotate_alm(64, alm_TGC, PI/3., 0.5_dp, 0.0_dp)
Transforms scalar and tensor
for
to emulate a rotation of the underlying map by
(
).
EXAMPLE:
use coord_v_convert, only: coordsys2euler_zyz
use alm_tools, only: rotate_alm
...
call coordsys2euler_zyz(2000.0_dp, 2000.0_dp, 'E', 'G', psi, theta, phi)
call rotate_alm(64, alm_TGC, psi, theta, phi)
Rotate the
from Ecliptic to Galactic coordinates.
RELATED ROUTINES
This section lists the routines related to rotate_alm*
-
coordsys2euler_zyz
- can be used to generate
the Euler angles
for rotation between standard astronomical coordinate systems
-
create_alm
- Routine to create
coefficients.
-
alter_alm
- Routine to modify
coefficients to apply or remove the effect of an instrumental beam.
-
map2alm
- Routines to analyze a HEALPix sky map into its
coefficients.
-
alm2map
- Routines to synthetize a HEALPix sky map from its
coefficients.
-
alms2fits, dump_alms
- Routines to save a set of
in a FITS file.
-
xcc_v_convert
- rotates a 3D coordinate
vector from one astronomical coordinate system to another.
Version 3.83, 2024-11-13