; Y2K ;--------------------------------------------------------------- ;! verifies correctness and performance using standard problems ;# RUN GENERAL ;----------------------------------------------------------------------- ;; Copyright (C) 2000, 2004-2005, 2007, 2019, 2022 ;; 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 ;--------------------------------------------------------------- Y2K LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC Y2K : Verification/timing test; see Y2KLOAD.001, Y2KEXEC.001 TCODE INIT, TEST, READ, or WRIT TMODE T or M; Test or Master input TMASK 1.0 127.0 test selection bit mask Y2KSIZE SMALL, MEDIUM, LARGE test DDISK 1.0 35.0 Disk drive #: master UVDATA MDISK 1.0 35.0 Disk drive #: other masters TDISK 1.0 35.0 Disk drive #: test images IOTAPE 1.0 9.0 Input/Output tape drive #. Y2KDISK Disk area for READ and WRIT EDGSKP 0.0 64.0 Pixels to skip at edges TERSE -1.0 99.0 > 0 => reduced output OUTPRINT Printer disk file to save BADDISK Disks to avoid VERSION ---------------------------------------------------------------- Y2K Type: RUN file Use: Y2K performs the AIPS verification test on an AIPS system. See RUN files Y2KLOAD.001 to compile a set of procedures and Y2KEXEC.001 to run them. This input file is used to prepare the parameters needed to run Y2KEXEC. Set the adverb values, do a TPUT Y2K, and then RUN Y2KEXEC. The idea is to run a sequence of the most commonly used tasks in AIPS on a standard UV data set. The tasks are UVSRT, IMAGR, APCLN, CALIB, and VTESS as the main tasks with tasks SUBIM, COMB, UVDIF, CCMRG, FITLD, and FITAB also being exercised. The test runs each task and compares the results with standard answers prepared when the test was devised or last revised. The total time it takes to execute may be used to compare computer performance and the degree to which the current answers agree with the official answers compares compilers/computers and code reliability/constancy. Adverbs: TCODE String*4 'INIT' - create new master files 'TEST' - test tasks against master files 'READ' - read master files from tape/disk 'WRIT' - write master files to tape/disk User sites would first READ the master files in and then TEST them. TMODE String*1 'T' - test output from previous task used as input to next task. 'M' requests master input to all tasks. TMASK Scalar Task selection bit mask (1-63) - use 63 normally. +1=>SORT, +2=>IMAGR, +4=>APCLN, +8=>CALIB, +16=>IMAGR-Clean, +32=>VTESS For example, TMASK=54 would execute all but sort and CALIB. Y2KSIZE String*8 'SMALL', 'MEDIUM', 'LARGE' test. The LARGE test is used to measure performance. There is also a 'HUGE' test. DDISK Scalar Disk drive # (1-9) master UVDATA MDISK Scalar Disk drive # (1-9) other master files TDISK Scalar Disk drive # (1-9) test files IOTAPE Scalar Input or output tape drive #. (1-9) Y2KDISK String*8 Logical name of disk area to be used for FITS-disk files in READ or WRIT instead of actual magnetic tape. ' ' => use magnetic tape. EDGSKP Scalar Number of pixels to skip at edges in comparing test and master images TERSE Scalar > 0 => reduced output: > 0 = drops INPUTS for all tasks and TPHEAD when reading tape > 2 = also drops CATALOG listings > 3 = also drops IMHEADER listings Use -1 on all new or uncertain systems, or when determining the AIPSMark(93). OUTPRINT String*48 Disk file name in which to save the line printer output. ' ' => use scratch and print immediately for interactive jobs - batch jobs use OUTPRINT = 'PRTFIL:BATCHjjj.nnn' (jjj = job #, nnn = user #). When OUTPRINT is not blank, multiple outputs are concatenated and the file is not actually printed. BADDISK Array Any bad disks to avoid for scratch files VERSION String*48 Version of tasks to use - normally blank to use TST. Other values include OLD, NEW, and private dirs; use | to separate entries in a search path. Y2K runs in four different modes: (TCODE) INIT = starts from the original master UV dataset, and (re)computes master files (does ALLDEST). The "mask" TMASK controls which steps execute. TEST = re-does the INIT computation but stores the new files under different names and compares against masters. The "mask" TMASK controls which steps execute. TEST steps use either the TEST run output of the previous step (TMODE=T) or the INIT run output (TMODE=M). WRIT = write master or test files to tape (TMODE matters) READ = read master files from tape. Input data files for test steps are selected by the TMODE adverb which has two possible values: 'T' for those made in previous steps of the present test or 'M' for the master "correct" data sets input from tape. The adverb Y2KSIZE controls the size of the test performed: 'S' 512x512 image, 5000 clean components, 15000 vis 'M' 1024x1024 image, 15000 clean components, 75000 vis 'L' 2048x2048 image, 25000/75000 Clean components, 425000 vis 'H' 4096x4096 images, APCLN not used, 4-resolution IMAGR used with 35000/200000 Clean components 2674490 vis. ---------------------------------------------------------------- Explanation of Y2K: Y2K exercises important AIPS tasks using data for one of four sources. The four data sets provide four sizes of "real" AIPS reduction: 512x512 with 13000 vis. and 5000 components; 1024x1024 with 77000 vis. and 15000 components; 2048x2048 images with 425000 vis and 25000/75000 Clean components and 4096x4096 images with a 4-resolution Clean on 2674490 vis with 35000 and 200000 Clean components. The sources for the "small" problem was originally a background sources for an HI absorption experiment by Liszt and Greisen, the "medium" problem uses data supplied by Alan Bridle, and the "large" and "huge" problems use data supplied by Rick Perley and Chris Carilli. The Y2K tests are intended to certify the correct execution of all AIPS systems. They are an enhancement of the DDT tests devised a decade earlier for the same purpose on computers of more modest capabilities. About DDT it was said: "The smallest is small enough to run in less than one day on all machines which will ever run AIPS." Its execution time is significant and easily measurable on modest systems such as the Sparc IPX, and approximate timings can also be obtained for faster systems. The AIPSmark(93) is based on the total elapsed time for the Large DDT suite; see AIPS memo 85 for full details. The AIPSmark(2000) has been defined in AIPS Memo 104 using the large Y2K test in a similar manner. This memo is available from our web site and is shipped with AIPS. The DDT test used task MX extensively. That task was retired since it used image projections which are no longer supported. Therefore the DDT test has also been retired. ================================================================ Steps to execute the Y2K Test on a new computer: 1. Log in to AIPS under the user number which will own the data files and the SAVE/GET files associated with the test. It is probably convenient to clear your AIPS message file before proceeding: PRNUM=-1; (PRTMSG possibly) ; CLRMSG 2. Now do the POPS command "RUN Y2KLOAD". This initiates the compilation process, which on most modern systems will not take more than a few minutes. 3. The next step is to read the data files from the tape, or from disk. On tape, these are files 1 - 10 for the small problem, files 11 - 20 for the medium problem, and files 21 - 39 for the large problem (which breaks the UV files into pieces). The HUGE test has never been put on tape, a large-capacity tape would be required. Alternately, if you have the files on disk, merely set the Y2KDISK adverb to point at where the files reside (you need to define or use a "logical" or environment variable with an uppercase name before starting AIPS to use this feature; e.g. FITS). The Y2K files are available via anonymous ftp to ftp.aoc.nrao.edu in directory cd pub/software/aips/FITS/31DEC22 prompt binary MGET Y2KL* (or Y2KS*, Y2KM*, Y2KH*) On tapes, the first one in each set is the original visibility data set of the Y2K problem. Subsequent files are the "master" versions of files computed from the original dataset. The read process consists of the following steps: CLRMSG GET Y2KINIT Specify DDISK, MDISK, TDISK, and IOTAPE or Y2KDISK Also specify BADDISK as needed Y2KSIZE='SMALL' or 'MEDIUM' or 'LARGE' or 'HUGE' (desired problem) TCODE='READ'; TMASK=63 TPUT Y2K (TPUT saves adverb values) MOUNT the tape unless you have the disk files RUN Y2KEXEC DISMOUNT the tape or remove/backup the disk files PRTMSG (documents data read process) In the case of a Y2K tape, the READ mode will rewind the tape and skip over the data for the smaller problems (if 'SMALL' wasn't given). It will then execute FITLD to read the UV and image files to disk. At the end of the process, it rewinds the tape and prints a directory of the disk files. NOTE: Y2KEXEC will insist on having non-default values for IOTAPE, DDISK, MDISK, and TDISK. 4. Now it is time to actually perform the test. The 'TEST' mode recomputes the various files. All map results are compared to the master versions which were read from tape in the previous step. There are two ways to perform the calculations: with each step computed from the result of the previous test calculation in the sequence, or else from the result of the previous MASTER computation in the sequence. The first mode (TMODE='T') tests how well the system under test is able to reproduce a complex sequence of calculations beginning from a designated starting point. That is, it measures the accumulation of error in the system. The second mode (TMODE='M') tests the steps of the sequence separately so that errors created in each step can be isolated. It is also the step used for calculating the AIPSmark(2000). Both tests are important, and both should be performed to certify fully the scientific adequacy of an AIPS installation, but it is generally best to use TMODE='M' as the initial (and primary) test of all systems. The steps are: CLRMSG (prepare for test results) GET Y2KINIT TGET Y2K TCODE='TEST'; TMODE='M'; TMASK=63 Y2KSIZE='SMALL' or 'MEDIUM' or 'LARGE' (desired problem) EDGSKP=4, 8, or 16 for small, medium or large/huge Y2KSIZE TPUT Y2K (saves the adverb values) RUN Y2KEXEC PRTMSG (print out the test results) For the AIPSmark values, TERSE should be set to -1. The message file from Y2KEXEC will be more than 2000 lines long. It is intended to be the major item documenting the test procedures and results. We usually test with messages coming to the xterm running the test - in other words, we kill the message server if one comes up. Making a second run with TMODE='T' is not required, but it may be advisable to evaluate the accumulation of error. This process also checks the manipulations of visibilities, antenna files, and gain files; these processes are not really tested in the 'M' mode because AIPS currently has no comparison operators for files of these types. The 'T' mode tests them by their effect on subsequent map results. This is particularly important for the output of the self-calibration program CALIB. One can also rerun the tests with a different value for the VERSION adverb. One can also use this option to test experimental versions of specific tasks. In the HUGE tests, the accuracy of the residual images after the first Clean is not as good as that of the other steps. This is normal and should not be a great concern. Typical inputs look like Y2K : Verification/timing test; see Y2KLOAD.001, Y2KEXEC.001 Adverbs Values Comments ---------------------------------------------------------------- TCODE 'TEST' INIT, TEST, READ, or WRIT TMODE 'M' T or M; Test or Master input TMASK 63 test selection bit mask Y2KSIZE 'LARGE ' SMALL, MEDIUM, LARGE test DDISK 2 Disk drive #: master UVDATA MDISK 2 Disk drive #: other masters TDISK 2 Disk drive #: test images IOTAPE 1 Input/Output tape drive #. Y2KDISK 'MYY2K ' Disk area for READ and WRIT EDGSKP 4 Pixels to skip at edges TERSE -1 > 0 => reduced output OUTPRINT 'FITS:Y2K.15Jan05 ' Printer disk file to save BADDISK *all 0 Disks to avoid VERSION ' ' where environment variable MYY2K is the data area used for the FITS disk files for Y2K data. A typical number of bits looks like: 'IMAGE' 13.1018839 15.531579 'IMBEAM' 13.8289413 16.6617813 'APCLN' 12.7427092 16.7804108 'APRES' 17.8541603 24.5266685 'IMCLN' 9.6245136 16.6369858 'VTESS' 15.2701616 23.2641563 'VTESSC' 16.6828175 20.8412228 The important timing lines are: 15:18:41 AIPS run y2ke .... 15:33:42 AIPS 'PRINTING MESSAGES SUGGESTIVE OF ERROR: PRIO > 5' giving 15:01 seconds elapsed time (901 sec or aipsmark 44) The PRTAC information summary confirms Version: ALL # tasks 20 Tot real 14.9 Tot cpu 10.231 Av cp/re .41414 the total real time and shows that the cpu/real performance of this machine was not particularly good. 5. The 'WRIT' mode tests task FITAB, while 'READ' tests FITLD. The basic idea is to produce a tape (or FITS disk files), and then to read that tape or those files on an AIPS system to verify that it yields correct results. It follows that generating a new tape with the 'WRIT' mode and then executing 'READ' and 'TEST' on it will also effectively test the tape tasks. Better yet, take the tape to another AIPS and run Y2K on it! This verifies the intercommunication of the systems. Obviously, use of FITS disk files will do little to test your tape I/O. Note that Y2K assumes that the tape consists of the 10 SMALL data files, followed by 10 MEDIUM data files, followed by 10 LARGE data files. You should first run Y2K in WRIT mode for the SMALL problem. If generating a tape, having done this, you may then (optionally) run Y2K in WRIT mode for the medium problem and, having done all this, you may then WRIT the LARGE problem. The steps are: CLRMSG GET Y2KINIT TGET Y2K Y2KSIZE='SMALL' or 'MEDIUM' or 'LARGE' (desired problem) TCODE='WRIT';TMODE='T' TPUT Y2K RUN Y2KEXEC PRTMSG (print out the test results) Note that when we say "tape", we mean either magnetic tape in the usual sense, or pseudo-tape disk files. The latter are selected by setting Y2KDISK to a non-blank value which is the logical name (environmental variable) for the disk area to be used. The disk files are given a fixed and obvious pattern of names (Y2Ksnnnnnn, where s is S, M,or L and nnnnnn is the image name related to the task name). The LARGE test divides the UV data files into "pieces" as defined by FITAB. 6. Finally, one wants to know the accounting statistics from the test runs. The accounting listing can be correlated with the message file listings in order to analyze the performance of the tested system. Y2K now runs task PRTAC to produce the desired information. Note that PRTAC has exclusive access to the accounting file until it finishes, and so various tasks may complain while they are waiting to get access to the file. In TEST mode, the listing produced by PRTAC will show only the last sequence of tasks suitable for the Y2K test. In other modes, it will list all tasks run in the last day or two. The columns of the listing give the taskname, POPS#, user#, start-time, real-time, CPU-time, and "IOCNT". Asterisks mark any run that aborted. After this basic sequential listing comes a listing by task name giving the totals accumulated by each task. The listing is given in two sort orders. ================================================================ Regarding "cloning": It is obvious that Y2KLOAD and Y2KEXEC are cloneable. First, a clone of Y2K could process another dataset; this would be done by adding additional allowed string values for Y2KSIZE and renaming the input UV data set DY2K?, where ? is the first character in the new allowed string value. The adverb values needed for the new data set, are initialized in the Y2KPROC procedure which is SAVEd in Y2KSAVE. Second, the general pattern of executing and testing the tasks in succession will work for a wide variety of AIPS tasks and data types. ================================================================ Interpretation of Test Results The results of the mapping tests are recorded as the number of BITS of accuracy. The BITS of accuracy are defined in two ways, by the MAX difference in the Master image and the Test image and by the RMS differences in the images. The BITS measured by the the base 2 logarithm of the ratio of PEAK and DIFFERENCE of the images. The BITS are calculated as -3.3219 * LOG(DIFF/PEAK). (LOG is the Base 10 Logarithm; 1/LOG(2) = 3.3219) The expected BITS of accuracy for the tasks are in the range of 10 to 20 BITS. The RMS BITS of accuracy is always greater than the PEAK BITS of accuracy. For further information on the interpretation of the results, refer to AIPS memo 85, 104, and other memos in the AIPS memo series that relate to the Y2K tests. These are available via anonymous ftp and the world wide web on the internet; ftp to ftp.aoc.nrao.edu, cd to pub/software/aips/TEXT/PUBL/ . The web page is http://www.aips.nrao.edu/