*+ * Name: * NDF_FUNC_DEF * Purpose: * Define statement functions for the NDF_ system. * Language: * Unix Fortran * Type of Module: * Function definition include file. * Description: * This file defines statement functions which are used internally by * the NDF_ system and which may also be used by other software which * calls NDF_ routines. * Notes: * - This file exists to encapsulate functions which require * non-portable Fortran and which may therefore need to be * implemented differently on different machines. It should be * preceded by the include file NDF_DEC which declares the functions * defined here together with their arguments. * Copyright: * Copyright (C) 1990 Science & Engineering Research Council. * Copyright (C) 1995 Central Laboratory of the Research Councils. * All Rights Reserved. * Licence: * 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., 51 Franklin Street,Fifth Floor, Boston, MA * 02110-1301, USA * Authors: * RFWS: R.F. Warren-Smith (STARLINK) * BKM: B.K. McIlwrath (STARLINK) * {enter_new_authors_here} * History: * 20-MAR-1990 (RFWS): * Original version. * 2-APR-1990 (RFWS): * Changed NDF_DEF to NDF_FUNC_DEF. * 29-NOV-1995: (BKM) * Linux version using FORTRAN extension AND(). * {enter_further_changes_here} * Bugs: * {note_any_bugs_here} *- * Internal References: *+ * Name: * NDF_QMASK * Purpose: * Determine if an NDF quality value and a "bad-bits" mask * dictate that an NDF pixel be included in processing. * Invocation: * (LOGICAL) RESULT = NDF_QMASK( QUAL, BADBIT ) * Arguments: * QUAL = BYTE (Given) * The unsigned byte quality value. * BADBIT = BYTE (Given) * The unsigned byte "bad-bits" mask. * Result: * NDF_QMASK = LOGICAL (Returned) * A .TRUE. value is returned if the bit-wise "AND" of the * quality and bad-bits values is zero, indicating that the NDF * pixel is not excluded by its quality value and should be * included in processing. Otherwise, a .FALSE. value is * returned, indicating that the pixel should be excluded from * processing. NDF_QMASK( NDF_ARGB1, NDF_ARGB2 ) = : IAND( NDF_ARGB1, NDF_ARGB2 ) .EQ. 0 *.