; IMCENTER ;----------------------------------------------------------------------- ;! returns pixel position of sub-image centroid ;# Verb Analysis ;----------------------------------------------------------------------- ;; Copyright (C) 2006 ;; Associated Universities, Inc. Washington DC, USA. ;; ;; This program is free software; you can redistribute it and/or ;; modify it under the terms of the GNU General Public License as ;; published by the Free Software Foundation; either version 2 of ;; the License, or (at your option) any later version. ;; ;; This program is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; ;; You should have received a copy of the GNU General Public ;; License along with this program; if not, write to the Free ;; Software Foundation, Inc., 675 Massachusetts Ave, Cambridge, ;; MA 02139, USA. ;; ;; Correspondence concerning AIPS should be addressed as follows: ;; Internet email: aipsmail@nrao.edu. ;; Postal address: AIPS Project Office ;; National Radio Astronomy Observatory ;; 520 Edgemont Road ;; Charlottesville, VA 22903-2475 USA ;----------------------------------------------------------------------- IMCENTER LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC IMCENTER: Verb to find coordinates of sub-image centroid INNAME Image name (name) INCLASS Image name (class) INSEQ 0.0 9999.0 Image name (seq. #) INDISK 0.0 9.0 Disk drive # BLC -1.0 Bottom left pixel TRC 0.0 Top right pixel FLUX Include pixels > FLUX PRTLEV -2.0 10.0 <= -1 => no display results @ Output adverbs PIXXY @ Fitted (X,Y,...) pixel of @ maximum. COORDINA @ Coordinates at pixel ERROR @ > 0 => fit failed, else okay ---------------------------------------------------------------- IMCENTER Type: Verb Use: IMCENTER reads a piece of an image and finds the intensity-weighted centroid. Adverbs: (inputs) INNAME......Image name(name). Standard defaults. INCLASS.....Image name(class). Standard defaults. INSEQ.......Image name(seq. #). 0 => highest. INDISK......Disk drive # of image. 0 => any. BLC.........Bottom left corner. If BLC = -1,r then do a circle of radius r pixels centered on the TRC position TRC.........Top right corner or center of circle in pixels FLUX........If FLUX > 0, ignore all image values below FLUX. If FLUX < 0, ignore all image values less than -FLUX in absolute value. WARNING: if FLUX is set too low, the centroid can be pulled away from the obvious position by more than one might first expect. PRTLEV......Print level: if <= -1, then do not put result info in message file, otherwise do a coordinate display Adverbs: (outputs) PIXXY.......Fitted (X,Y,...) position of centroid 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 (all pixels < FLUX), ERROR will be TRUE (1), else it will be FALSE (-1). Used to detect failures without stopping a procedure or RUN file. ----------------------------------------------------------------