- Form: CUT dest source [PA=n] [C=(r,c)] [W=w] [NORM] [L=h]
[OFF=f] [TV] [PROF] [DPA=dpa]
-
- dest
- (integer or $ construct) is an image which
will hold the calculated cut profile,
- source
- (integer or $ construct) is the image (object)
from which the cut is to be measured,
- PA=n
- sets the position angle of radial slice through the
extended object,
- C=(r,c)
- resets the center of the slice from the AXES values,
- L=l
- Sets the length of the cut in pixels,
- W=w
- Sets the cut width in pixels,
- NORM
- Normalizes by the cut width,
- OFF=f
- Offsets the cut from the center in the width direction.
- TV
- Shows the area of the cut on the TV.
- PROF
- Plots using information from PROFILE common block (center,
position angle, sky
- DPA=dpa
- Using PROF option, plots at an angle dpa degrees from
PROFILE pa
CUT will extract the surface-brightness profile of an object along an
arbitrary position angle. The center of the object can be loaded with the
AXES command or by the C keyword. A cut can also be offset from any center
using the OFF keyword, as might be done to take a series of cuts at
different locations along the major axis of a galaxy. The position angle
is defined from the top of the image. Adding 180 to any PA will generate a
cut running in the opposite direction. This can be used to compare or add
profiles reflected about the center of a galaxy, for example. The default
width is one pixel, and the height or length extends to the image borders.
Both parameters are rounded to the nearest whole pixel. The PLOT keyword
shows the bounds of the cut on the image display.
The cut is loaded into the 'dest' image buffer, and can be treated,
analyzed, processed, saved, etc., as an image with a row dimension of one.
The central column of the cut is always set to occur at column 0. Sinc
interpolation is used to generated cuts of width 1; bilinear interpolation
is used otherwise. Pixels are always summed across the width of the cut.
Divide the resulting cut vector by the width in pixels (WIDTH= keyword) to
normalize it after the fact.
See Also: AXES, TEMPLATE