- Form: TVPLOT [with keywords below as needed]
-
- P=(r,c)
- Enter a position (use twice as needed)
- L=l
- Enter line length
- C=(r,c)
- Enter center (row, column)
- TEXT=s
- Plot text in quotes or string variable
- BOX=n
- Plot image subsection box number n
- BOX
- Plot boxes other than predefined image boxes
- W=w
- Enter width of box
- H=h
- Enter height of box
- CROSS
- Plot cross
- CIRC=rad
- Plot a circle
- COMPASS=rad
- Plot a compass
- TICKS
- Put ticks marks on line
- SCALE=s
- Use pixel scale for all lengths
- PA=f
- Position angle
- OFF=d
- Offset of graphics from center
TVPLOT is used to markup, label, annotate, or otherwise deface the image
display. It has loads of options and clever use of defaults, so you don't
have to say everything. The origin of the plots is from a predefined
center loaded by the AXES command or is given by the C= keyword.
In simple use TVPLOT will draw lines. Use just L=l, or just P= for the
default center, or two P=(r,c) endpoints to ignore the default origin. Use
SCALE if you mean arcseconds for L and not pixels, PA to rotate, or OFF to
give an offset in whatever direction the X axis is for any PA
specification. TICKS will give nice scale marks on the line.
Show the image subsection boxes (see BOX) with BOX=n. You can also make up
any boxes just for plotting by giving the BOX keyword. This tells TVPLOT
to think about BOX plotting instead of lines. Use W and H with the default
center or C= keyword, two P= keywords to give opposite corners, P and C
together for corners, any of L, W, or H by themselves for square boxes, and
so on. Use PA, OFF, SCALE to help out.
Other symetrical plots. Here you have CROSS, CIRC=r, COMPASS=r, all of
which follow the AXES, C=, or P= centers. Use PA, OFF, SCALE here, too.
Now you can make any label you want with the TEXT option - except you can't
rotate it with PA (sorry - it uses system fonts that I didn't want to muck
with). Use P=, or C= to position it - where you give where you want the
center of the string to be. Right now VISTA has a little trouble with
multiword strings enterred directly on the TVPLOT command line, but they
work fine if you load them first with the STRING command.
Examples:
- AXES 1 BOX=7
- Find the center of the object within
the BOX 7 subsection of image 1.
- TVPLOT BOX=7
- Plot this same box on the TV.
- TVPLOT CIRC=10
- Draw a 10-pixel radius circle around it.
- TVPLOT CROSS
- Mark it with a cross.
- TVPLOT COMPASS=20
- a really cool map compass
- STRING BIGDEAL 'This is the object in BOX 7'
-
- TVPLOT TEXT=BIGDEAL
- Label the stupid thing.
O.K. so now you want real vector graphics.
- TVPLOT P=(101,237)
- This will draw a line from where ever
the center is to row=101, col=237.
- TVPLOT P=(r1,c1) P=(r2,c2)
- OK, this is your standard line
between any two points.
- TVPLOT BOX P=(r1,c1) P=(r2,c2)
- Makes a box instead of a line.
- TVPLOT TEXT=BIGDEAL P=(r,c)
- Stick a label anywhere.
Use procedures to make a neat grid at a funny angle.
YDIM=25
XDIM=15
FUNNY=37
STEP=5
DO Y=-YDIM,YDIM,STEP
TVPLOT P=(-XDIM,Y) P=(XDIM,Y) PA=FUNNY
END_DO
DO X=-XDIM,XDIM,STEP
TVPLOT P=(X,-YDIM) P=(X,YDIM) PA=FUNNY
END_DO