; IMVAL ;--------------------------------------------------------------- ;! returns image intensity and coordinate at specified pixel ;# Verb Analysis Catalog ;----------------------------------------------------------------------- ;; Copyright (C) 1995, 2003, 2006, 2009, 2012 ;; 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 ;----------------------------------------------------------------------- IMVAL LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC IMVAL: Determines pixel value at specified position w messages INNAME Image name(name). INCLASS Image name(class). INSEQ 0.0 9999.0 Image name(seq. #). 0=>high INDISK 0.0 9.0 Disk drive #. 0=>any PIXXY 0.0 4096.0 (X,Y,...) pixel in image DOCENTER -1.0 1.0 > 0 -> value at pixel else cubic interpolate @ Output adverbs PIXVAL @ Intensity at PIXXY. COORDINA @ Coordinates at pixel ERROR @ > 0 => fit failed, else okay ---------------------------------------------------------------- IMVAL Type: Verb Use: IMVAL does a cubic interpolation of the image value at the image location specified by PIXXY (in pixels) and returns the value in PIXVAL. The coordinate is also returned. It reports the pixel position, pixel value, and coordinates at message level 5. Verb QIMVAL is faster since it does not report the results. Adverbs (input): 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. PIXXY.......(X,Y,...) pixel location in image. NOT zero on the X and Y axes anyway. DOCENTER....> 0 => find value at closest pixel to PIXXY <= 0 => do a cubic interpolation about PIXXY Adverbs (output): 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 interpolation fails, ERROR will be TRUE (1), else it will be FALSE (-1). ----------------------------------------------------------------