From owner-fitsbits at kochab.cv.nrao.edu Wed Oct 13 10:56:35 1999 Received: (from majordom at localhost) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) id KAA15236 for fitsbits-spinner; Wed, 13 Oct 1999 10:55:32 -0400 (EDT) Received: from fits.cv.nrao.edu (IDENT:dwells at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id KAA15231 for ; Wed, 13 Oct 1999 10:55:29 -0400 (EDT) Received: (from dwells at localhost) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) id KAA27180 for fitsbits at majordomo.cv.nrao.edu; Wed, 13 Oct 1999 10:55:28 -0400 Received: from fits.cv.nrao.edu (IDENT:root at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id JAA15125 for ; Wed, 13 Oct 1999 09:45:35 -0400 (EDT) Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) with ESMTP id JAA26646 for ; Wed, 13 Oct 1999 09:45:34 -0400 Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.7/8.8.8/CV-2.2) id JAA16724; Wed, 13 Oct 1999 09:45:33 -0400 To: fitsbits at cv.nrao.edu Date: Wed, 13 Oct 1999 14:52:02 +0200 From: Eric Aristidi Message-ID: <38048072.DF9D7848 at unice.fr> Organization: University of Nice Sophia-Antipolis Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntp-out.monmouth.com!newspeer.monmouth.com!remarQ-easT!remarQ.com!supernews.com!isdnet!ciril.fr!cines.fr!unice.fr!not-for-mail Subject: Read FITS from Octave/Matlab Newsgroups: sci.astro.fits Sender: owner-fitsbits at kochab.cv.nrao.edu Precedence: bulk Hello, Anybody knows wether it exists matlab function for reding FITS files ? Thanks for help -- Eric Aristidi Dpt Astrophysique - Universite de Nice, Parc Valrose, 06108 Nice Cedex 2 mail : aristidi at unice.fr fax : +33 4 92 07 63 21 phone : +33 4 92 07 63 45 http://www-astro.unice.fr/PagePerso/aristidi/ From owner-fitsbits at kochab.cv.nrao.edu Wed Oct 13 10:56:40 1999 Received: (from majordom at localhost) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) id KAA15243 for fitsbits-spinner; Wed, 13 Oct 1999 10:56:01 -0400 (EDT) Received: from fits.cv.nrao.edu (IDENT:dwells at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id KAA15238 for ; Wed, 13 Oct 1999 10:55:58 -0400 (EDT) Received: (from dwells at localhost) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) id KAA27186 for fitsbits at majordomo.cv.nrao.edu; Wed, 13 Oct 1999 10:55:57 -0400 Received: from fits.cv.nrao.edu (IDENT:root at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id UAA10506 for ; Tue, 12 Oct 1999 20:11:04 -0400 (EDT) Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) with ESMTP id UAA25851 for ; Tue, 12 Oct 1999 20:11:03 -0400 Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.7/8.8.8/CV-2.2) id UAA01082; Tue, 12 Oct 1999 20:11:03 -0400 To: fitsbits at cv.nrao.edu Date: 12 Oct 1999 21:29:42 GMT From: "F.Cavicchio" Message-ID: <01bf14f8$e2190a40$d887d8d4 at privato> Organization: TIN Path: newsfeed.cv.nrao.edu!chaos.aoc.nrao.edu!newshost.nmt.edu!newshost.lanl.gov!awabi.library.ucla.edu!128.230.129.106!news.maxwell.syr.edu!bignews.mediaways.net!newsfeed.nettuno.it!server-b.cs.interbusiness.it!news.tin.it!not-for-mail Subject: Avis FITS Viewer Newsgroups: sci.astro.fits Sender: owner-fitsbits at kochab.cv.nrao.edu Precedence: bulk Our new, freeware FITS Viewer AVIS is now available for download at the following URL: http://www.sira.it/msb/avis.htm Features: Opens FITS files: (8 & 16 bit), supports multiple file opening and drag & drop from Explorer and other Windows shells. Imports CCD files: like SBIG ST8, ST7, ST6, ST5, ST4, Starlight, Hisis, Pixcell and others. Imports graytones TIFF and TGA files. Saves FITS and allows modifications of the FITS Header. Exports files as TXT format, RAW, TIFF, TGA, BMP and JPEG. On-line help: full documentation about Avis and about FITS file format. Hi, F.Cavicchio. From owner-fitsbits at kochab.cv.nrao.edu Wed Oct 13 11:15:32 1999 Received: (from majordom at localhost) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) id LAA15294 for fitsbits-spinner; Wed, 13 Oct 1999 11:15:30 -0400 (EDT) Received: from fits.cv.nrao.edu (IDENT:dwells at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id LAA15289 for ; Wed, 13 Oct 1999 11:15:27 -0400 (EDT) Received: (from dwells at localhost) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) id LAA27259 for fitsbits at majordomo.cv.nrao.edu; Wed, 13 Oct 1999 11:15:27 -0400 Received: from cv3.cv.nrao.edu (cv3.cv.nrao.edu [192.33.115.2]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id LAA15267 for ; Wed, 13 Oct 1999 11:12:29 -0400 (EDT) Received: from palantir.cv.nrao.edu (IDENT:tismail at palantir.cv.nrao.edu [192.33.115.254]) by cv3.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id LAA15117 for ; Wed, 13 Oct 1999 11:12:25 -0400 (EDT) Received: (from tismail at localhost) by palantir.cv.nrao.edu (8.8.5/8.8.5) id LAA17477 for ; Wed, 13 Oct 1999 11:12:22 -0400 Received: from lheapop.gsfc.nasa.gov(128.183.16.62) by palantir.cv.nrao.edu via smap (V1.3) id sma017452; Wed Oct 13 11:11:51 1999 Received: from silk.gsfc.nasa.gov (d660-80120.gsfc.nasa.gov [128.183.18.120]) by lheapop.gsfc.nasa.gov (LHEA9504/950407.s1) with ESMTP id LAA18182; Wed, 13 Oct 1999 11:09:41 -0400 Message-ID: <3804A0E0.37DED0DD at silk.gsfc.nasa.gov> Date: Wed, 13 Oct 1999 11:10:24 -0400 From: tam Organization: NASA/GSFC(USRA) X-Mailer: Mozilla 4.7 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Eric Aristidi CC: fitsbits at nrao.edu Subject: Re: Read FITS from Octave/Matlab References: <38048072.DF9D7848 at unice.fr> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-fitsbits at kochab.cv.nrao.edu Precedence: bulk There is a listing for a FITS Matlab library written by Peter Rydesater in our table of FITS libraries at http://heasarc.gsfc.nasa.gov/docs/heasarc/fits/fits_libraries.html I believe this library provides only support for FITS images. Regards, Tom McGlynn Eric Aristidi wrote: > > Hello, > > Anybody knows wether it exists matlab function for reding FITS files ? > > Thanks for help > > -- > Eric Aristidi From owner-fitsbits at kochab.cv.nrao.edu Wed Oct 20 08:31:21 1999 Received: (from majordom at localhost) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) id IAA28096 for fitsbits-spinner; Wed, 20 Oct 1999 08:31:18 -0400 (EDT) Received: from fits.cv.nrao.edu (IDENT:dwells at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id IAA28091 for ; Wed, 20 Oct 1999 08:31:15 -0400 (EDT) Received: (from dwells at localhost) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) id IAA15951 for fitsbits at majordomo.cv.nrao.edu; Wed, 20 Oct 1999 08:31:14 -0400 Received: from fits.cv.nrao.edu (IDENT:root at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id EAA25812 for ; Wed, 20 Oct 1999 04:58:38 -0400 (EDT) Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) with ESMTP id EAA15570 for ; Wed, 20 Oct 1999 04:58:37 -0400 Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.7/8.8.8/CV-2.2) id EAA28923; Wed, 20 Oct 1999 04:58:37 -0400 To: fitsbits at cv.nrao.edu Date: Tue, 19 Oct 1999 23:08:46 GMT From: "Martino Nicolini" Message-ID: <2S6P3.27825$i06.315949 at typhoon.libero.it> Organization: [Infostrada] Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!newsfeed.mathworks.com!EU.net!newssrv.ita.tip.net!i2unix!typhoon.libero.it!not-for-mail Subject: [fitsbits] AVIS FITS viewer Newsgroups: sci.astro.fits Sender: owner-fitsbits at kochab.cv.nrao.edu Precedence: bulk There is a new FITS viewer at the page: http://www.sira.it/msb/avis.htm AVIS is a freeware FITS viewer for Windows 95, 98 and NT. Features: - opens FITS files: (8 & 16 bit), supports multiple file opening and drag & drop from Explorer and other Windows shells; - imports CCD files: like SBIG ST8, ST7, ST6, ST5, ST4, Starlight, Hisis, Pixcell and others. Imports graytones TIFF and TGA files; - saves FITS and allows easy and fast modifications of the FITS Header; - exports files: as TXT format, RAW, TIF, TGA, BMP and JPEG; - supports WCS (World Coordinates System); - custom palettes; - on-line help: full documentation about AVIS and introduction to FITS file format. Enjoy this Italian software! Martino Nicolini ******************************************** OSS. ASTRONOMICO "G. MONTANARI" - CAVEZZO via Concordia, 200 - 41032 Cavezzo (MO) ITALY MPC 107 Tel. ++39 0535-58755 E-mail: oss_astr_cav at arcanet.it WEB: http://www.arcanet.it/oss_astronomico/ Personal E-mail: mnico at iol.it ******************************************** From owner-fitsbits at kochab.cv.nrao.edu Wed Oct 20 08:31:33 1999 Received: (from majordom at localhost) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) id IAA28089 for fitsbits-spinner; Wed, 20 Oct 1999 08:31:06 -0400 (EDT) Received: from fits.cv.nrao.edu (IDENT:dwells at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id IAA28084 for ; Wed, 20 Oct 1999 08:31:03 -0400 (EDT) Received: (from dwells at localhost) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) id IAA15946 for fitsbits at majordomo.cv.nrao.edu; Wed, 20 Oct 1999 08:31:03 -0400 Received: from fits.cv.nrao.edu (IDENT:root at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id AAA22838 for ; Wed, 20 Oct 1999 00:54:55 -0400 (EDT) Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) with ESMTP id AAA15307 for ; Wed, 20 Oct 1999 00:54:54 -0400 Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.7/8.8.8/CV-2.2) id AAA27007; Wed, 20 Oct 1999 00:54:53 -0400 To: fitsbits at cv.nrao.edu Date: Tue, 19 Oct 1999 21:55:02 -0700 From: jack_72 at hotmail.com (Jack Thomas) Message-ID: Organization: AT&T WorldNet Services Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntp-out.monmouth.com!newspeer.monmouth.com!howland.erols.net!news-out.worldnet.att.net.MISMATCH!wn3feed!worldnet.att.net!wnmaster1!not-for-mail Subject: [fitsbits] best program Newsgroups: sci.astro.fits Sender: owner-fitsbits at kochab.cv.nrao.edu Precedence: bulk What is the best program to work with fits formats (for a MacIntosh)? Thanks From owner-fitsbits at kochab.cv.nrao.edu Mon Oct 25 15:35:57 1999 Received: (from majordom at localhost) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) id PAA04365 for fitsbits-spinner; Mon, 25 Oct 1999 15:33:34 -0400 (EDT) Received: from fits.cv.nrao.edu (IDENT:dwells at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id PAA04360 for ; Mon, 25 Oct 1999 15:33:31 -0400 (EDT) Received: (from dwells at localhost) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) id PAA26551 for fitsbits at majordomo.cv.nrao.edu; Mon, 25 Oct 1999 15:33:31 -0400 Received: from fits.cv.nrao.edu (IDENT:root at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id PAA03823 for ; Mon, 25 Oct 1999 15:30:34 -0400 (EDT) Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) with ESMTP id PAA26532 for ; Mon, 25 Oct 1999 15:30:34 -0400 Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.7/8.8.8/CV-2.2) id PAA01137; Mon, 25 Oct 1999 15:30:33 -0400 To: fitsbits at cv.nrao.edu Date: Mon, 25 Oct 1999 15:05:00 -0400 From: "Derek Schulze" Message-ID: <7v29kf$p43$1 at knot.queensu.ca> Organization: Queen's University, Kingston Path: newsfeed.cv.nrao.edu!chaos.aoc.nrao.edu!lynx.unm.edu!jobone!newsxfer3.rs.itd.umich.edu!newsfeed.berkeley.edu!howland.erols.net!torn!news.ccs.queensu.ca!not-for-mail Subject: [fitsbits] importing FITs files... Newsgroups: sci.astro.fits Sender: owner-fitsbits at kochab.cv.nrao.edu Precedence: bulk I am trying to find a way to get FITs files into any common viewer that would be capable of appending the files together to form a single stacked file of images (eg; NIH Image, ImageJ, ImageTool). Could I make a MOV or AVI out of a series of FITs files? Anyone out there have any ideas? Thanks. From owner-fitsbits at kochab.cv.nrao.edu Fri Oct 29 14:10:19 1999 Received: (from majordom at localhost) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) id OAA14117 for fitsbits-spinner; Fri, 29 Oct 1999 14:07:11 -0400 (EDT) Received: from fits.cv.nrao.edu (IDENT:dwells at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id OAA14112 for ; Fri, 29 Oct 1999 14:07:08 -0400 (EDT) Received: (from dwells at localhost) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) id OAA08364 for fitsbits at majordomo.cv.nrao.edu; Fri, 29 Oct 1999 14:07:07 -0400 Received: from fits.cv.nrao.edu (IDENT:root at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id NAA14060 for ; Fri, 29 Oct 1999 13:31:38 -0400 (EDT) Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) with ESMTP id NAA08187 for ; Fri, 29 Oct 1999 13:31:37 -0400 Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.7/8.8.8/CV-2.2) id NAA00192; Fri, 29 Oct 1999 13:31:37 -0400 To: fitsbits at cv.nrao.edu Date: Fri, 29 Oct 1999 10:21:55 -0400 From: Paul Barrett Message-ID: <3819AD83.E38C006A at stsci.edu> Organization: Space Telescope Science Institute, Baltimore, MD 21218 Path: newsfeed.cv.nrao.edu!chaos.aoc.nrao.edu!newshost.nmt.edu!rutgers!faatcrl.faa.gov!hammer.uoregon.edu!logbridge.uoregon.edu!enews.sgi.com!coop.net!ncar!noao!stsci.edu!not-for-mail Subject: [fitsbits] Some FITS ambiguities Newsgroups: sci.astro.fits Sender: owner-fitsbits at kochab.cv.nrao.edu Precedence: bulk I have three questions about version 2.0 of the FITS standard that the NOST document doesn't appear to cover. 1) What is the recommended procedure for handling a keyword value that is >4294967296 (i.e. a 32-bit unsigned integer), or similarly, >18446744073709551616 (ie. a 64-bit unsigned integer)? Note that in fixed format an integer can have 20 digits. If they are all 9s, the integer is greater than a 64-bit unsigned integer. And in free format, integers can have 70 digits. How are these numbers to be handled? By a BCD library? 2) What is the practical difference between a null string (i.e. '') and a blank string (i.e. ' ')? See page 16 of the FITS standard. They are both strings. Does it really matter if one has 8 spaces and the other 0 spaces? 3) The FITS standard notes that a series of digits with leading zeros is considered a decimal number, not an octal number as found in many programming languages. (Kind of a shame really.) The FITS standard does not note whether this is also true for floating point numbers. Can floating point values contain leading zeros? -- Dr. Paul Barrett Space Telescope Science Institute Phone: 410-516-6714 DESD/DPT FAX: 410-516-8615 Baltimore, MD 21218 From owner-fitsbits at kochab.cv.nrao.edu Fri Oct 29 18:56:25 1999 Received: (from majordom at localhost) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) id SAA14451 for fitsbits-spinner; Fri, 29 Oct 1999 18:54:56 -0400 (EDT) Received: from fits.cv.nrao.edu (IDENT:dwells at fits.cv.nrao.edu [192.33.115.8]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id SAA14446 for ; Fri, 29 Oct 1999 18:54:53 -0400 (EDT) Received: (from dwells at localhost) by fits.cv.nrao.edu (8.9.3/NRAO/CV-2.0) id SAA09909 for fitsbits at majordomo.cv.nrao.edu; Fri, 29 Oct 1999 18:54:52 -0400 Received: from cv3.cv.nrao.edu (cv3.cv.nrao.edu [192.33.115.2]) by kochab.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id QAA14242 for ; Fri, 29 Oct 1999 16:22:52 -0400 (EDT) Received: from milkyway.gsfc.nasa.gov (milkyway.gsfc.nasa.gov [128.183.16.143]) by cv3.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with SMTP id QAA22208 for ; Fri, 29 Oct 1999 16:22:50 -0400 (EDT) Received: from tetra.gsfc.nasa.gov (tetra.gsfc.nasa.gov [128.183.16.178]) by milkyway.gsfc.nasa.gov (LHEA9504/950407.s1) with ESMTP id QAA13941; Fri, 29 Oct 1999 16:22:16 -0400 Received: from tetra.gsfc.nasa.gov (localhost [127.0.0.1]) by tetra.gsfc.nasa.gov (8.8.8+Sun/8.8.8) with ESMTP id QAA24811; Fri, 29 Oct 1999 16:22:15 -0400 (EDT) Message-ID: <381A01F7.C968F151 at tetra.gsfc.nasa.gov> Date: Fri, 29 Oct 1999 16:22:15 -0400 From: William Pence Organization: NASA/GSFC X-Mailer: Mozilla 4.51 [en] (X11; U; SunOS 5.6 sun4u) X-Accept-Language: en MIME-Version: 1.0 To: Paul Barrett CC: fitsbits at nrao.edu Subject: Re: [fitsbits] Some FITS ambiguities References: <3819AD83.E38C006A at stsci.edu> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-fitsbits at kochab.cv.nrao.edu Precedence: bulk Paul Barrett wrote: > > I have three questions about version 2.0 of the FITS standard that the > NOST document doesn't appear to cover. Here's my opinion: > 1) What is the recommended procedure for handling a keyword value that > is >4294967296 (i.e. a 32-bit unsigned integer), or similarly, > >18446744073709551616 (ie. a 64-bit unsigned integer)? > > Note that in fixed format an integer can have 20 digits. If they are all > 9s, the integer is greater than a 64-bit unsigned integer. And in free > format, integers can have 70 digits. How are these numbers to be > handled? By a BCD library? The FITS Standard does not restrict the range of integer keyword values, so you can write as many digits as will fit on the line (70). It is then an implementation detail as to how such large values should be handled by FITS reading software. This will probably vary from application to application. > 2) What is the practical difference between a null string (i.e. '') and > a blank string (i.e. ' ')? See page 16 of the FITS standard. > They are both strings. Does it really matter if one has 8 spaces and the > other 0 spaces? Conceptually at least, there is a difference between the two: a null string ('') is a string that has a null or undefined value. A blank string on the other hand has a defined value that consists of a sequence of blanks. The Standard says that trailing blanks are not significant, so I would interpret the first blank to be significant and any following blanks to be insignificant (others might disagree with this interpretation however). The distinction between null and blank strings may be lost in some languages (e.g. Fortran 77) which do not naturally support the concept of a null string. A keyword should be given a null string value if the value is unknown at the time of writing the keyword, but may be possibly updated at a later time with a known value. A blank string should be used if it is known that the string is blank (e.g. if a keyword gives the middle initial of the observer, then it should be blank if the observer has no middle name, and null if it is not known whether the observer has a middle name). In practice, I doubt if this distinction is very important, except in certain special applications which might want to use it. Note that there is yet a third case in which a keyword can have no value, e.g. RVALUE = / comment field In this case the datatype as well as the value of the keyword are both undefined (unless the keyword is specifically defined to have a certain datatype in the Standard). > 3) The FITS standard notes that a series of digits with leading zeros is > considered a decimal number, not an octal number as found in many > programming languages. (Kind of a shame really.) The FITS standard > does not note whether this is also true for floating point numbers. Can > floating point values contain leading zeros? Yes. The Standard does not explicitly mention this case because there is little ambiguity about how to interpret the value of floating point numbers containing leading zeros, unlike the integer case. -Bill Pence ____________________________________________________________________ Dr. William Pence pence at tetra.gsfc.nasa.gov NASA/GSFC Code 662 HEASARC +1-301-286-4599 (voice) Greenbelt MD 20771 +1-301-286-1684 (fax)