; IF ;--------------------------------------------------------------- ;! causes conditional execution of a set of POPS statements ;# PseudoVerb POPS ;----------------------------------------------------------------------- ;; 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 ;----------------------------------------------------------------------- ;--------------------------------------------------------------- IF LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC ---------------------------------------------------------------- IF Type: Psuedoverb - procedure only Use: To execute conditionally a set of statements or decide between two sets of statements based on a logical relation. Grammar: IF condition THEN statement1;... ELSE statementn;...; END Or: IF condition THEN statement1;...;END where condition is a relational condition using =, <=, >=, <>, &, ! or a logical variable. Statements are AIPS statements. The statements may be separated by semi- colons as shown above or they may be on separate lines. IF-THEN-ELSE may be used in procedures only. Examples: IF A = B THEN PRINT 'A = B'; A=7; ELSE PRINT 'A <> B'; A=8; END IF A <= B THEN PRINT 'A <= B'; C=9; END ----------------------------------------------------------------