; UVBXFN ;--------------------------------------------------------------- ;! type of function used when counting for uniform weighting ;# ADVERB UV IMAGING ;----------------------------------------------------------------------- ;; Copyright (C) 1995 ;; 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 ;----------------------------------------------------------------------- ;--------------------------------------------------------------- UVBXFN LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC ---------------------------------------------------------------- UVBXFN Type: Adverb (Real) Use: The type of function used when counting for uniform weighting. If UVBOX = 0, this is irrelevant since all functions are 1 at the center cell. If UVBXFN < 0, the function is taken as a function in U and V [i.e. the counting weight = f(du)*f(dv)]; if UVBXFN > 0, the function is taken as a function in radius [i.e. the counting weight = f(sqrt(du*du+dv*dv))] giving everything approxiamtely circular support. If ABS(UVBXFN) = K, then K = 1 : Pill box f(x) = 1 (x <= UVBOX) K = 2 : linear f(x) = 1 - x / (UVBOX+1) K = 3 : exponential f(x) = exp(-2x/(UVBOX+1)) K = 4 : Gaussian f(x) = exp(-(2x/(UVBOX+1))**2) Other details: f(x) >= 0 and f(x) = 0 when x > UVBOX. du and dv take only integer values: 0, 1, 2, ... UVBOX. Null value: 0 => 1, < -4 => -1, > 4 => 1 Tasks: IMAGR.....Fourier transform and Clean UV data with a full range of calibration, weighting, Cleaning, and wide-field correction options. ----------------------------------------------------------------