cubsmooth
NAME
cubsmooth - pixel smoothing and resampling
SYNOPSIS
cubsmooth
[ -x range | -x_range range ]
[ -x_step value | -x_sampling value ]
[ -x_width value ]
[ -x_smooth_kernel name | -x_kernel name ]
[ -y range | -y_range range ]
[ -y_step value | -y_sampling value ]
[ -y_width value ]
[ -y_smooth_kernel name | -y_kernel name ]
[ -z range | -z_range range ]
[ -z_step value | -z_sampling value ]
[ -z_width value ]
[ -z_smooth_kernel name | -z_kernel name ]
[ -xy_step value | -xy_sampling value ]
[ -yz_step value | -yz_sampling value ]
[ -zx_step value | -zx_sampling value ]
[ -xy_width value ]
[ -yz_width value ]
[ -zx_width value ]
[ -xy_smooth_kernel name | -xy_kernel name ]
[ -yz_smooth_kernel name | -yz_kernel name ]
[ -zx_smooth_kernel name | -zx_kernel name ]
DESCRIPTION
The command changes actual resolutions for the data cube
and make resampling.
The command make three dimensional smoothing simaltenuously at each
new sampling point.
If you want to smooth along axes independently,
you should use the command step by step.
Smoothing along the velocity and the sky extension is such case.
The data with the dummy pixel value are neglect for smoothing process.
The statistical informations about pixel value stored in the header of
cub are automatically recalculated.
FILTER TYPE
.cub | cubsmooth | .cub
OPTIONS
- -x range | -x_range range
- The coverage along the first axis (x) of the resultant cube.
The range is composed of two values devided by the character ",".
If the value is angle, you can use the
ASTROS standard angle expression.
If the value is velocity, you can use in km/s.
If the value is frequency, you can use in GHz.
In other cases the value is in the same unit as the cub has, which
can be checked by cubheadls.
- -x_step value | -x_sampling value
- The resampling step along the first axis (x) of the resultant cube.
If the value is angle, you can use the
ASTROS standard angle expression.
If the value is velocity, you can use in km/s.
If the value is frequency, you can use in GHz.
In other cases the value is in the same unit as the cub has, which
can be checked by cubheadls.
- -x_width value
- The smoothing width along the first axis (x).
If the value is angle, you can use the
ASTROS standard angle expression.
If the value is velocity, you can use in km/s.
If the value is frequency, you can use in GHz.
In other cases the value is in the same unit as the cub has, which
can be checked by cubheadls.
- -x_smooth_kernel name | -x_kernel name ]
- The name of kernel function type for convolution.
The following are supported at present.
- hunning
- three neighboring channels with weight 1:2:1
- gauss
- gaussian
- box | boxcar
- boxcar type, uniform weighting with a finite width
- bin
- binning or binding.
The same as boxcar type but one original datum is only used for one new datum.
- pin | pinpoint
- take the same value as the nearest one pixel in original data
- -y_... value, -z_... value
- The same as -x_... but for the second and third axes (y,z),
respectively.
- -xy_... value, -yz_... value, -zx_... value
- The first type is the same as both -x_... and -y_... simultaneously.
The -yz_... means -y_... and -z_..., and the -zx_... means -z_... and -x_....
This, "2-axis-simultaneous input method", is useful,
if two of axes of the data are longitude and latitude.
DEFAULTS
- -x 0,0 -y 0,0 -z 0,0 -x_step 0 -y_step 0 -z_step 0
-x_width 0 -y_width 0 -z_width 0
-x_kernel pin -y_kernel pin -z_kernel pin -prm smooth.prm
- If x_range and x_step are all 0 (the same as default),
x_range is automatically set to the whole span of the original,
and
x_step is automatically set to the same step of the original.
This automatic setting is the same as for other axes.
SEE ALSO
cubload, cubsave, .cub
flipaxis, cubheadcorr
BUGS
- In some cases longitude span beyond 360 degree cannot be dealed with well.
- When the kernel type is gauss or box, corresponding width must be asigned.
It should be automatically set to proper value using corresponding step, but is not.
- The command does not work well for data cube with
negative delta between pixels. You should use flipaxis command.
- The command does not check the matching of the physical meaning
of two axes,
even if you give parameters with the "2-axis-simultaneous input method".
HISTORY
- ver.3.02
- 1999/12/27 T.Handa
- ver.3.03
- 2002/5/11 T.Handa
- ver.3.04
- 2002/6/30 T.Handa
- ver.3.05
- 2003/3/3 T.Handa
- ver.3.06
- 2003/8/28 T.Handa
- ver.3.07
- 2003/8/30 T.Handa
MANUAL VERSION
- 2003/8/30 T.Handa
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