; QCREATE ;--------------------------------------------------------------- ;! adverb controlling the way large files are created ;# ADVERB UV IMAGING ;----------------------------------------------------------------------- ;; Copyright (C) 2011 ;; 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 ;----------------------------------------------------------------------- QCREATE LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC ---------------------------------------------------------------- QCREATE Type: Adverb (Real) Use: Controls how files > 1 Mbyte are created. If <= 0, the files are created on disk by filling the entire requested space with zeros. This guarantees that the disk space is reserved and initialized but can take a long time for files of many Gbytes. If > 0, files are created by writing a buffer or 2 of zeros at the requested end of file so that the file will appear to be as big as desired. However, the parts not filled with zeros are not reserved and might not be available when the task gets around to writing them. It also trusts all AIPS programs to not assume that the disk is zero to begin with. The up side of this method is that it is very fast and, if you have lots of disk space, the danger of running out is minimal. This parameter is used on all file creations - effectively it is an adverb to the pseudo-verb GO. ----------------------------------------------------------------