- Form: POLAR dest source [PA=f] [E=e] [C=(r,c)] [NORM]
[SINC] [R=(rmin,rmax)]
-
- dest
- is the destination image buffer. It does not need
to exist beforehand.
- source
- is the image buffer to transform
- PA
- is PA of object's major axis
- E
- gives its ellipticity = 1-b/a
- C
- gives its row and column center
- NORM
- renormalize pixel intensities
- SINC
- use high-resolution sinc interpolation.
- R
- gives the radial limits of the new grid
POLAR will transform the image in the `source' buffer from observed
Cartesian coordinates (x,y) to polar coordinates (r,theta) in the `dest'
buffer. The transformation assumes that the object is intrinsically round
and projected into an ellipse in the sky plane with the given position
angle, ellipticity (1-b/a) and center.
The SINC keyword instructs ROUND to use high-accuracy sinc interpolation
instead of the default bilinear interpolation algorithm.
The NORM keyword is used to renormalize the pixel intensities (surface
brightness/pixel) in the transformed image.
The R=(rmin,rmax) keyword is used to specify the radial limits of the
r-axis of the polar deprojection. By default, if R= is not given the
r-axis will run from 0 to the maximum semi-major axis of the inscribed
ellipse.
See Also: ROUND