Table of Contents

This program also handles 2D images, in
which case the output is a table, consisting of 6 columns:

rad = outer radius of the annulus; npix = number of pixels in the annulus; int = average in the annulus; (no support for median yet) rms = rms in the annulus; sum = sum in the annulus; cumsum = cumulative sum for all annuli so far.This is the same order and meaning as the table from

The
particle based program *snapshell(1NEMO)*
does something similar in 3D.

The
metric of how the radius is computed can be changed using the **metric=** keyword.
For metric=2 these would be called true rings, for metric=1 a square.

**in=**- input data cube. No default.
**radii=**- radii of the ring
boundaries (Nring+1). See
**metric=**below for different ways to change the metric of computing a radius. No default. **pa=**- position angle of disk, astronomical convention. [0]
**inc=**- inclination angle of disk [0]
**center=**- rotation center (mapcenter if left blank, 0,0=lower left)
**vsys=**- systemic velocity. Only needed for cube. [0]
**blank=**- Value of the blank pixel to be ignored [0.0]
**norm=**- Normalize values to number of pixels in ring. This only has an effect on the image written, not on the table, which uses both. [t]
**out=**- RV image, useful for 3D cubes. If not given, no image will be written. Default: not used
**tab=**- Output table, useful for 2D images. If not give, no table will be written. Default: not used
**rscale=**- Convenience factor by which radii are multiplied for display in the table. For FITS images this is usually 3600. [1]
**iscale=**- Convenience factor by which intensities are multiplied for display in the table. For FITS images this is usually 1 / (1.133*(beam/pixel)**2). [1]
**metric=N**- The exponent of the r^N = x^N + y^N metric to compute a radius.
N=2 is the traditional cartesian [2]

A value of **metric=1** can be interesting, though the position angle may need
to be adjusted, as the box is mis-aligned by 45 degrees from the major axis.
For large values of **metric** the box is aligned along the major axis.

% ccdgen out=- object=gauss spar=1,50 size=256,256 | ccdellint - 0:100:5 tab=- 5 80 0.997464 0.00145455 79.7971 79.7971 10 236 0.987487 0.00426892 233.047 312.844 ... 95 2924 0.180558 0.0096899 527.951 13127.6 100 3056 0.149281 0.00837475 456.204 13583.8

For a map in K.km/s that needs to be converted to Jy.km/s, with Jy/K=2.5 and
a beam of 12.65 arcsec and 5.5 pixels there are 6 points per beam, therefore
the rscale=3600 is needed to view the table in arcsec, and iscale=2.5/6
for viewing in Jy.km/s:

% fitsccd M100_97520_99703.mom0.fits - |\ ccdellint - 0:250/3600:10/3600 pa=150 inc=40 center=45,45 rscale=3600 iscale=1.41/0.65/6.00 tab=- 10 7 16.3524 0 114.467 114.467 20 24 11.824 0 283.776 398.243 .. 240 290 0.0505762 0 14.6671 3057.86 250 241 -0.0573514 0 -13.8217 3044.04

Some examples of PPV->RV

% fitsccd ngc6503.cube.fits - |\ ccdellint - 0:1000/3600:10/3600 pa=-60 inc=40 center=163,122 out=ngc6503.rv.ccd norm=f

30-nov-2020V0.1 draftedPJT 23-nov-2022V0.3 confirmed 2D images, added table outputPJT 6-dec-2022V0.6 use metric= to allow other radius methodsPJT