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Description and Examples
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Description and Examples
Description
alm2dl reads
and calculates
and
where
![\begin{displaymath}
C_{{\ell}}=\frac{1}{2{\ell}+1}\sum_{m=-{\ell}}^{{\ell}} \vert a_{{\ell}m}\vert^2.
\end{displaymath}](img4.png) |
(1) |
![\begin{displaymath}
D_{{\ell}}=\frac{ {\ell}({\ell}+1)C_{{\ell}}}{2 \pi T_0^2}.
\end{displaymath}](img5.png) |
(2) |
where
K,
is output
in unit of
and
is unitless.
alm2dl can read the input
file either in FITS or in ASCII formats.
The FITS binary format should contain 3 fields: index=
(in HEALPix
definition),
real part (
) and
imaginary part (
). The ASCII
format should contain 4 entries : L, M, Re, Im,
where L is the
-multipole and M is the
-multipole.
alm2dl
calculates
amplitudes:
and phases defined as
in
.
alm2dl
also lists the values of the FITS
coefficients, which can be output either to a file or to the
standard output device for display.
Examples
- Calculating
or
:
- Listing
:
- Calculating amplitudes:
- alm2dl -amp alm.fits -lmax 10
reads ' alm.fits' and calculates
amplitudes up to
.
- alm2dl -amp -a alm.txt -lmax 50 -o
amp.txt
reads ASCII ' alm.txt' and
outputs
ASCII amplitudes up to
in ' amp.txt'.
- Calculating phases:
- alm2dl -ph alm.fits -lmax 10
reads ' alm.fits' and displays
phases up to
.
Next: cl2map
Up: GLESP
Description and Examples
Previous: GLESP
Description and Examples
Gauss Legendre Sky Pixelization