Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.atnf.csiro.au/computing/software/gipsy/tsk/slice.dc1 Дата изменения: Wed Jul 5 16:05:25 1995 Дата индексирования: Fri Jan 16 00:08:18 2009 Кодировка: Поисковые слова: universe

Program: SLICE

Purpose: Make a slice through a set

Category: MANIPULATION, COORDINATES, HEADER, PLOTTING

File: slice.c

Author: M.G.R. Vogelaar

Keywords:

INSET= Give set, subsets:
Maximum number of subsets is 4096.
Dimension of the subsets must be 2.

POSITION= Give central position: [0,0]

ANGLE= Give angle (deg), w.r.t North towards the East:

GRIDOUT= New grid spacing of [spacing in longitude]
rotated axis:

POINTS= Give number of pixels on rotated axis:
[Number of pixels on longitude axis]

SLICES= Number of slices above and below slice [0,0]
through new projection centre.
Total number of slices cannot exceed 256.

SPACE= Spacing between slices: [grid spacing in latitude]

OUTSET= Give output set:

PLOT= Create plot of slice? Y/[N]
If you want to now how the slices are orientated
in your box, select PLOT=Y. A box is plotted and labeled
and the slices in the first subset are displayed.
The following keywords can be specified now:


PGPLOT keywords:

GRDEVICE= Plot device: [List of devices]
Destination of plot, Screen or Hardcopy.

PGMOSAIC= View surface sub divisions in x,y: [1,1]
View surface can contain a number of plots in
in X and Y direction (mosaic). Default is 1 plot in
both X- and Y direction.

PGPAPER= Give width(cm), aspect ratio: [calc, calc]
Aspect ratio is height/width.

PGBOX= Corners of box Xl,Yl,Xh,Yh: [default by application]
It is possible to overrule the calculated
PGPLOT box size with PGBOX=. The coordinates (x,y) of
the lower point are given first.

** PGCOLOR= Give color 1..15: [1]
See description for the available colors.

** PGWIDTH= Give line width 1..21: [2]

** PGHEIGHT= Give character height: [1.0]

** PGFONT= Give font 1..4: [2]

** PGSYMBOL= Give symbol number 0..127: [1]



Description: The program SLICE allows you to extract a plane from
a data set (INSET=) under an arbitrary angle. The
extracted plane is stored in an output set (OUTSET=)
that has the same axis structure as the input set.
The subsets you define in the input must be two
dimensional and must have two spatial axes. The
number of subsets determine the length of the third
axis in the output (usually the spectral axis) and
must be less than 4096.
You can think of the output as a set where the longitude
axis originates from a rotated and/or shifted axis in the
input set. The number of pixels in the latitude direction
depends on the number of parallel slices you want to
extract. In order to view for example a LV plane in GIDS
you specify something like:

VIEW INSET=M8320SLICE d 0


The central position (POSITION=) is used to determine
the position of the rotation centre. The positions can be
prefixed (according to the documentation of dcdpos.dc3).
For example, if you want the new central position in
input pixel coordinates (-10.680130, -8.700096) and
position (0,0) in your input corresponds to the physical
coordinates 198.468100, 46.002610 deg. you specify:

POSITION=-10.680130 -8.700096 (pixels) or:
POSITION= U 198.493667 U 45.983306 (deg, deg) or:
POSITION= * 13 13 58.48 * 45 58 59.90 (hms, dms)

The position angle of the major axis of a galaxy is
defined as the angle taken in anti-clockwise direction
between the north direction in the sky and the major axis
of the receding half of that galaxy (Rots 1975) astron,
astrophys 45, 43. If you want a slice through this galaxy
specify ANGLE=
The program takes care of the fact that your original
latitude axis perhaps does not align with the north.

POINTS= gives the number of pixels on the rotated axis
and the value in GRIDOUT= determines which pixels of
the input are taken into account. If your new spacing
exceeds a certain value, it will be possible that pixels
are examined outside the input frame. The program
substitudes blanks for these positions.
Parallel slices (in real space) can be constructed if
you specify SLICES= The default is no extra slices.
If SLICES=n, m you get slices n pixels below and m
output pixels above the central slice. The grid spacing
of these output pixels are given in SPACE=


Color indices:

0 Background
1 Default (Black if background is white)
2 Red
3 Green
4 Blue
5 Cyan
6 Magenta
7 Yellow
8 Orange
7 Yellow
8 Orange
9 Green + Yellow
10 Green + Cyan
11 Blue + Cyan
12 Blue + Magenta
13 Red + Magenta
14 Dark Gray
15 Light Gray
16-255 Undefined

Available fonts:

1 single stroke "normal" font
2 roman font
3 italic font
4 script font



Notes: If Hermes is in TEST MODE, there is extra output to
the screen about properties of all axes in the input set.

Example:

Updates: Sep 12, 1991: VOG, Document created.
Apr 12, 1995: VOG, removed extra 'PGLAB' code.