Table of Contents

The first two dimension must be radius and angle, there can be an optional 3rd dimension, but it must be 1 slice in Z only.

The (2D)
four-point interpolation that is used in regridding
is based on the one in *cmhog/movie.src*, but includes correct interpolations
for points that are created if **periodic=t** is used. The program is not well
designed to detect errors in the amount of periodicity (e.g. creating a wedge
from -1 to 1 radian, and setting periodic=t will probably result in awkward
looking images.

**in=***hdf_sds*- Input file (HDF SD). No default.
**out=***image*- Output file, in
*image(5NEMO)*format. **select=***frame_no*- Select which
SDS from the file (1=first). See also
**zvar=**below. [Default:**1**]. **nx=***X_pixels*- Number of pixels in X. [Default:
**256**] **ny=***Y_pixels*- Number of pixels in Y
[Default:
**256**]. **xrange=***xmin:xmax*- Range in X [Default:
**-16:16**]. **yrange=***ymin:ymax*- Range in Y [Default:
**-16:16**]. **zvar=***grid_var*- Gridding variable. Normally
left alone, unless certain allowed mathematical expressions on the direct
griddable variables (as defined by
**select=**) need to be overriden. Allowed are**vr**(select=1),**vt**(select=2),**den**(select=3),**vx**,**vy**,**vm**and**vp**. Note that**vm**and**vp**are special cases of a linear combination of**vx**,**vy***vm = (vx-vy)/sqrt(2)*and*vp = (vx+vy)/sqrt(2)*, just to get an idea of the velocity field under a "middle" position angle. ** currently not implemented yet ** Default: not used, select= is used. **periodic=t|fP**- Attempt to fill the
plane by making the data periodic. ** currently only periodic=t works **
[Default:
**t**]. **z=***z-value*- Select a z-slice (0=first) from the RPZ cube if NZ > 1. By default the first (or only for 2D data) slice is used.
**order=***{z,p,r}*- Order of HDF axes. Note again that the order of axes in HDF is defined in
C order (eg. as seen in
*tsd(1NEMO)*), where the first printed axis is the slowest varying axis (usually the Z axis in an R-P-Z cube. But we still would call this cube with**order=zpr**

hdfwedge hdf010aa den010.ccd select=4 nx=256 ny=256 xrange=-8:8 yrange=-8:8

zvar= and periodic= do not work yet.

The algorithm tries to find how many multiples of the wedge are needed to fill 2.pi, and adds a shadow zone at either end to simplify dealing with coordinates close the -X axis. Wedges that are close to, but not exactly, whole fractionals of 2.pi can result in a shadow zone that is offset by 2. The program will detect this and attempt to repair this roundoff error (or a dataset with questionable choices of the boundary). This will occur for odd sized PHI axis, but is now fixed as a special case.

visit: http://www.llnl.gov/visit/

17-dec-04V0.1 createdPJT 20-dec-04V0.2 repair files with 2-step shadow zonesPJT 23-dec-04V0.3 fixed for odd sized Nphi filesPJT 26-oct-06V0.5 use z= to handle 3D cubesPJT