; DDT ;--------------------------------------------------------------- ;! verifies correctness and performance using standard problems ;# RUN GENERAL ;----------------------------------------------------------------------- ;; Copyright (C) 1995-1996, 2005 ;; 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 ;--------------------------------------------------------------- DDT LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC DDT : Verification/timing test; see DDTLOAD.001, DDTEXEC.001 TCODE INIT,TEST,READ, or WRIT TMODE T or M; Test or Master input TMASK 1.0 127.0 test selection bit mask DDTSIZE SMALL,MEDIUM,LARGE,HUGE 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 0.0 9.0 Input/Output tape drive #. DDTDISK 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 ---------------------------------------------------------------- DDT Type: RUN file Use: DDT performs the AIPS verification test of an AIPS system. See RUN files DDTLOAD.001 and DDTEXEC.001. The purpose of the inputs file is to perform bounds checks on the parameters and to enable the use of TPUT and TGET. *********************************************************** NOTE THAT THE DDT TEST HAS BEEN SUPERCEDED BY THE Y2K TEST. IT IS STILL MAINTAINED, BUT Y2K IS WHAT IS USUALLY USED. *********************************************************** Adverbs: TCODE String*4 'INIT', 'TEST', 'READ', or 'WRIT' TMODE String*1 'T' or 'M'; Test output from previous task as input to current. 'M' requests master input to all tasks. TMASK Scalar test selection bit mask (1-127) DDTSIZE String*8 'SMALL', 'MEDIUM', 'LARGE' 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 AND output tape drive #. (1-9) DDTDISK 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 OLD,NEW,OLDPSAP,NEWPSAP,LOCAL (also private dirs; use | to separate) DDT 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. A binary mask controls which steps of the test execute: TMASK +1=>SORT, +2=>UVMAP, +4=>APCLN, +8=>CALIB, +16=>MXmap, +32=>MXclean, +64=>VTESS For example, TMASK=54 would execute UVMAP,APCLN,MXmap,and MXclean. 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 DDTSIZE controls the size of the test performed: 'S' 256x256 image, 2000 clean components, 8000 vis 'M' 512x512 image, 5000 clean components, 15000 vis 'L' 1024x1024 image, 15000 clean components, 75000 vis ---------------------------------------------------------------- Explanation of DDT: (DCW, Feb/Mar85, EWG Nov85, CF Mar89, GL Jan90, PM Sep94) DDT exercises the "Dirty Dozen" of AIPS tasks using data for one of three sources. The three data sets provide three sizes of "real" AIPS reduction: 256x256 images with 8000 vis. and 2000 components, 512x512 with 13000 vis. and 5000 components, and 1024x1024 with 77000 vis. and 15000 components. The sources for the "small" and "medium" problems were originally background sources for an HI absorption experiment by Liszt and Greisen while the "large" problem uses data supplied by Alan Bridle. The DDT problem is intended to be used to certify the correct execution of all AIPS systems. (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. ================================================================ Steps to execute the DDT 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 DDTLOAD". This initiates the compilation process, which on most modern systems will not take more than a few minutes. You may want to execute the POPS command "PRTMSG" afterwards to document the compilation of the test procedures. 3. The next step is to read the data files from the tape, or from disk. On tape, these are files 1 - 11 for the small problem, files 12 - 22 for the medium problem, and files 23 - 33 for the large problem. Alternately, if you have the files on disk, merely set the DDTDISK 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 DDT files are available via anonymous ftp to ftp.aoc.nrao.edu in directory cd pub/software/aips/FITS/31DEC04 prompt binary MGET DDTL* (or DDTS*, DDTM*) On tapes, the first one in each set of 11 is the original visibility data set of the DDT problem. Subsequent files are the "master" versions of files computed from the original dataset. The read process consists of the following steps: CLRMSG GET DDTINIT Specify DDISK, MDISK, TDISK, and IOTAPE or DDTDISK Also specify BADDISK as needed DDTSIZE='SMALL' or 'MEDIUM' or 'LARGE' (desired problem) TCODE='READ'; TPUT DDT (TPUT saves adverb values) MOUNT the tape unless you have the disk files RUN DDTEXEC DISMOUNT the tape or remove/backup the disk files PRTMSG (documents data read process) In the case of a DDT 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: DDTEXEC will insist on having non-default values for IOTAPE or DDTDISK, 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 also should use tape. It is also the step used for calculating the AIPSmark(93). 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 DDTINIT TGET DDT TCODE='TEST'; TMODE='M'; TMASK=127 DDTSIZE='SMALL' or 'MEDIUM' or 'LARGE' (desired problem) EDGSKP=4, 8, or 16 for small, medium or large DDTSIZE TPUT DDT (saves the adverb values) RUN DDTEXEC PRTMSG (print out the test results) For the AIPSmark(93) benchmark, TERSE should be set to -1. The message file from DDTEXEC will be more than 2000 lines long. It is intended to be the major item documenting the test procedures and results. Making a second run with TMODE='T' is not required, but is generally 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. 5. The 'WRIT' mode tests task FITTP, 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 DDT 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 DDT assumes that the tape consists of the 11 SMALL data files, followed by 11 MEDIUM data files, followed by 11 LARGE data files. You should first run DDT in WRIT mode for the SMALL problem. If generating a tape, having done this, you may then (optionally) run DDT in WRIT mode for the medium problem and, having done all this, you may then WRIT the LARGE problem. The steps are: CLRMSG GET DDTINIT TGET DDT DDTSIZE='SMALL' or 'MEDIUM' or 'LARGE' (desired problem) TCODE='WRIT';TMODE='T' TPUT DDT RUN DDTEXEC 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 DDTDISK 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 (DDTsnnnnnn, where s is S, M, L, or H and nnnnnn is the image name related to the task name). 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. DDT 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. The listing produced by PRTAC will have one line for each execution of any task or program AIPS. 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 DDTLOAD and DDTEXEC are cloneable. First, a clone of DDT could process another dataset; this would be done by adding additional allowed string values for DDTSIZE and renaming the input UV data set DDDT?, where ? is the first character in the new allowed string value. The adverb values needed for the new data set, are initialized in the DDTPROC procedure which is SAVEd in DDTSAVE. 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 and other memos in the AIPS memo series that relate to the DDT tests. These are available via anonymous ftp and the world wide web on the internet; ftp to aips.nrao.edu, cd to /pub/aips/TEXT/PUBL/ . The web page is http://www.cv.nrao.edu/aips/ .