AIPS HELP file for TVMAXFIT in 31DEC22
As of Fri Jan 21 14:20:53 2022
TVMAXFIT: Procedure to find coordinates and values on the TV
IMSIZE 3.0 16.0 Search area for peak value.
PRTLEV -2.0 10.0 <= -1 => no display results
DOINVERS -1.0 1.0 > 0 fit peak in negative of
@ Output adverbs
INNAME @ Image name (name)
INCLASS @ Image name (class)
INSEQ @ Image name (seq. #)
INTYPE @ Image physical type ('MA')
INDISK @ Disk number
PIXXY @ Pixel location (X,Y,...) in
@ image - last chosen
PIXVAL @ Intensity at PIXXY.
COORDINA @ Coordinates at pixel
ERROR @ > 0 => fit failed, else okay
TVBUT @ Value of last button = 8.
Instructions will also appear on terminal.
Use: TVMAXFIT is a simple procedure that loops reading TV
cursor positions with IMXY and returning the image value
and coordinates at an maximum near that location to the
terminal and message file with MAXFIT. Hit button A, B,
or C to select a location. Hit button D to exit.
MAXFIT fits a quadratic function to a 3x3 map array to
determine the position and strength of an extremum. In
this procedure, the cursor position when the button is
hit is used as an estimate of the center of the 3x3
array. The fit will search over an area of IMSIZE pixels
for the actual peak value before fitting.
IMSIZE......(X,Y) search area in pixels. Verb uses 11 if
the values are outside the range 3 to 16.
PRTLEV......Print level: if <= -1, then do not put result info
in message file, otherwise do the coordinate and
DOINVERS....<= 0 -> do the fit in the image values, thus a positive
going peak even in an all negative image will be
found and fit
> 0 -> do the fit in the negative of the image values;
this is needed for a negative going bump.
INSEQ.......Image name(seq. #).
INDISK......Disk drive # of image.
PIXXY.......Pixel location (X,Y,...) in the image. The last
one selected is returned.
PIXVAL......Intensity at this pixel.
COORDINA....The X and Y coordinates are found as:
Xpos = abs(CO(1)) + abs(CO(2))/60 + abs(CO(3))/3600
if any of CO(1), CO(2), CO(3) < 0: Xpos = -Xpos
Ypos = abs(CO(4)) + abs(CO(5))/60 + abs(CO(6))/3600
if any of CO(4), CO(5), CO(6) < 0: Ypos = -Ypos
Note that, although these are most suited to RA, Dec in
sexagesimal notation, they can be used for any type of
coordinate. The units are standard FITS units (e.g
degrees, m/sec, Hz, sec, etc.) except that right
ascensions are in hours of time.
ERROR.......If the verb is not aborted for error, but the fit
fails, ERROR will be TRUE (1), else it will be
FALSE (-1). Procedure exits if ERROR is TRUE.
See EXPLAIN MAXFIT.