Floating point numbers are generated and written to unit 20 in the standard EP format using default values. Note the dimension of IBUF(900) to accept the default blocksize of 1800 16-bit units. The user's data is stored in the array A.
PROGRAM EPEXA1
DIMENSION IBUF(900),A(300)
CALL EPINIT
DO 10 I=1,20
CALL USER(A,NW)
C
C ROUTINE -USER- HAS STORED NW VALUES IN A TO BE WRITTEN OUT
C
CALL EPOUTS(20,3,NW,A,IBUF,IERR)
IF(IERR.NE.0)STOP 1
10 CONTINUE
C **********************************************************
C
C THE FOLLOWING CALL IS ESSENTIAL
C
C **********************************************************
CALL EPCLOS(20,IBUF,IERR)
C
C FOLLOWING CALL ONLY NECESSARY ON SOME COMPUTERS (UNIVAC,IBM)
C
CALL EPEND(20,IBUF,IERR)
IF(IERR.NE.0)STOP 2
STOP
END
Essentially similar to the previous example, a file is created using all defaults. Note the dimension of IBUF(480).
PROGRAM EPEXA2
DIMENSION IBUF(480),IA(300)
CALL EPINIT
DO 10 I=1,30
NW=10*I
CALL USER(IA,NW)
C
C ROUTINE -USER- HAS STORED NW VALUES IN A TO BE WRITTEN OUT.
C .....
CALL EPOUTS(20,3,NW,IA,IBUF,IERR)
IF(IERR.NE.0)STOP 1
10 CONTINUE
C **********************************************************
C
C THE FOLLOWING CALL IS ESSENTIAL
C
C **********************************************************
CALL EPCLOS(20,IBUF,IERR)
C
C FOLLOWING CALL ONLY NECESSARY ON SOME COMPUTERS (IBM, UNIVAC)
C
CALL EPEND(20,IBUF,IERR)
IF(IERR.NE.0)STOP 2
STOP
END
SUBROUTINE USER(IA,NW)
DIMENSION IA(NW)
DO 5 J=1,NW
IA(J)=J
5 CONTINUE
RETURN
END
This example treats data written with "long" blocks with a maximum size of 14400 bytes. Note the call to EPSETW to specify the buffer size correctly for a 32-bit computer.
PROGRAM EPEXA3
DIMENSION IA(300),BUF(3600)
CALL EPINIT
CALL EPSETW(10,1,7200,IERR)
C --- LOOP UNTIL EOF, OR ANY OTHER ERROR
1 CONTINUE
CALL EPREAD(10,3,NW,IA,BUF,IERR)
IF(IERR.NE.0) GOTO 20
C --- PROCESS CONTENTS OF A
C
CALL USER(IA,NW)
C
C --- LOOP
GOTO 1
20 STOP
END
SUBROUTINE USER(IA,NW)
DIMENSION IA(NW)
PRINT*,NW,(IA(I),I=1,5)
RETURN
END
Read the file of section 
.
Note the the conversion routine CFRIBM.
PROGRAM EPEXA4
DIMENSION A(300),BUF(480)
CALL EPINIT
C--- LOOP UNTIL EOF, OR ANY OTHER ERROR
1 CONTINUE
CALL EPREAD(10,3,NW,A,BUF,IERR)
IF(IERR.NE.0) GOTO 20
CALL CFRIBM(A,NW,3)
C--- PROCESS CONTENTS OF A
C
CALL USER(A,NW)
C
C--- LOOP
GOTO 1
20 STOP
END
Do the same as in the example in section ,
but this time with a bigger buffer
and convert data to IBM format for portability (CTOIBM).
PROGRAM EPEXA5
DIMENSION IBUF(4500),A(3000)
CALL EPINIT
C--- INCREASE OUTPUT BUFFER = PHYSICAL BLOCK LENGTH TO 9000 16-BIT
C WORDS (18000 BYTES), CORRESPONDING TO 4500 32-bit words
CALL EPSETW(20,1,9000,IERR)
IF(IERR.NE.0) STOP 1
DO 10 I=1,20
CALL USER(A,NW)
C
C ROUTINE -USER- HAS STORED NW VALUES IN A TO BE WRITTEN OUT.
C .....
C--- NOW CONVERT TO IBM FLOATING POINT FORMAT + WRITE
CALL CTOIBM(A,NW,3)
CALL EPOUTS(20,3,NW,A,IBUF,IERR)
IF(IERR.NE.0)STOP 2
10 CONTINUE
C **********************************************************
C
C THE FOLLOWING CALL IS ESSENTIAL
C
C **********************************************************
CALL EPCLOS(20,IBUF,IERR)
IF(IERR.NE.0)STOP 3
STOP
END
Read the file written in the previous example (EPEXA5) on a 32-bit computer, using CFRIBM to convert the real numbers to the local representation.
PROGRAM EPEXA6
DIMENSION A(3000),BUF(4500)
CALL EPINIT
C--- INCREASE INPUT BUFFER = PHYSICAL BLOCK LENGTH TO 9000 16-BIT
C WORDS (18000 BYTES), CORRESPONDING TO 4500 32-bit words
CALL EPSETW(10,1,9000,IERR)
IF(IERR.NE.0) STOP 1
C--- LOOP UNTIL EOF, OR ANY OTHER ERROR
1 CONTINUE
CALL EPREAD(10,3,NW,A,BUF,IERR)
IF(IERR.NE.0) GOTO 20
C--- THE FOLLOWING CALL HAS NO EFFECT ON IBM (MAY BE LEFT
C IN FOR CODE COMPATIBILITY)
CALL CFRIBM(A,NW,3)
C--- PROCESS CONTENTS OF A
C
CALL USER(A,NW)
C
C--- LOOP
GOTO 1
20 STOP
END
Read a tape on unit 10, with a maximum event size of 1000 words, unpacked as 16-bit words. After some reduction results are stored in array IRECO with a limit of 300 words. These results are then output to unit 20 packed 32-bits/word. The block size for both units is the EP package default (1800 16-bit words). Note the mandatory call to EPCLOS for the output unit at the end.
PROGRAM EPEXA7
DIMENSION IBUF(900),IBUFO(900),IRECI(1000),IRECO(300)
CALL EPINIT
C-- SET INPUT STATUS WORDS \ SETTING WORD 2 PREVENTS PROGRAM
C-- OVERWRITING SHOULD YOU HAVE BAD DATA
CALL EPSETW(10,2,1000,IERR)
IF(IERR.NE.0)STOP 1
C THE FOLLOWING CALL IS OPTIONAL; USEFUL TO VERIFY OPTIONS
CALL EPSTAT
C-- READ A RECORD, UNPACK AS 16-BIT WORDS
50 CALL EPREAD(10,2,NW,IRECI,IBUF,IERR)
IF(IERR.NE.0)GOTO 500
PRINT*,NW
C-- DATA REDUCTION PART \ NWO WORDS OF DATA ARE STORED IN IRECO
C-- NWO CAN VARY BUT THE MAXIMUM IS 300, DEFINED BY EPSETW CALL
C-- NWO WORDS
C--
CALL USER(NWO,IRECO)
C-- THE OUTPUT IS PACKED 32-BITS PER WORD
CALL EPOUTS(20,3,NWO,IRECO,IBUFO,IERR)
IF(IERR.NE.0)GOTO 600
GOTO 50
C-- READ ERRORS
C-- PARITY AND OTHER
500 IF(IERR.NE.1)GOTO 50
C-- EOF
CALL EPCLOS(20,IBUFO,IERR)
CALL EPEND(20,IBUFO,IERR)
STOP
C-- WRITE ERRORS
600 STOP 600
END
The package provides utility routines to convert to and from ASCII 8-bit character code, which is the way we recommend to write text.
Since the package uses a 16-bit word as basic unit, the user should read and write Hollerith strings as bit strings (MODE=1), and pad with a blank to an even number of characters if necessary.
Of the computers for which this package exists, only IBM and CDC do not use the ASCII code internally. IBM uses 8-bit EBCDIC, CDC uses 6-bit DISPLAY code. However, when reading and writing on VAXes, the bytes in successive pairs of bytes have to be swapped in order to come out correctly, since they get swapped again when reading or writing, to make 16-bit words look correct.
Consequently, there exist two routines, SFRASC and STOASC on IBM, CDC, and VAX which perform the necessary conversion or swapping. The following examples show how they are used.
The previous routines CFRASC and CTOASC, working on blown-up strings will continue to exist.
The following example shows how to write Hollerith strings using both the old and new routines.
PROGRAM EPEXA9
DIMENSION IBIG(1000),ISMALL(1000),IBUF(1000),STRING(22)
DATA STRING/
1 'ABCD','EFGH','IJKL','MNOP','QRST','UVWX','YZab','cdef',
2 'ghij','klmn','opqr','stuv','wxyz','0123','4567','89+-',
3 '*/()','$=,.','#[]:','"_!&',4H'?<>,'@---'/
C
C NW IS THE NUMBER OF CHARACTERS
C
NW= 88
CALL EPINIT
C
C USE PREVIOUS ROUTINES ( BLOW, CONVERT, BUNCH )
C
CALL BLO8W(STRING,1,IBIG,1,NW)
CALL CTOASC(IBIG,NW)
CALL BUN8W(IBIG,1,ISMALL,1,NW)
C
C WRITE AS-BIT STRING (NOTE NUMBER OF 16-BIT WORDS ! )
C
CALL EPOUTS(11,1,(NW-1)/2+1,ISMALL,IBUF,IERR)
C
C--- String Conversion Routines add same string behind first, write again
C
CALL STOASC(STRING,1,ISMALL,NW+1,NW)
CALL EPOUTS(11,1,NW,ISMALL,IBUF,IERR)
CALL EPCLOS(11,IBIG,IERR)
CALL EPEND(11,IBIG,IERR)
STOP
END
This example shows the use of SFRASC to read and convert the
character strings from the file created in the example in
section .
PROGRAM TEST
DIMENSION IBUF(1000),IASC(1000)
CALL EPINIT
10 CONTINUE
CALL EPREAD(11,1,NW,IASC,IBUF,IERR)
IF(IERR.NE.0) STOP
CALL SFRASC(IASC,1,IASC,1,2*NW)
NW=NW/2
PRINT 2001,NW,IERR
2001 FORMAT(/" NO. OF WORDS =",I5," ERROR =",I3)
PRINT 2002,(IASC(I),I=1,NP)
2002 FORMAT(/1X,25A4)
GOTO 10
END
This example shows typical values to use for OLD format HP or NORD tapes read on the CDC. Note IBUF(512) and the corresponding number of 16-bit words is 1920, and the call to EPREAD with MODE=2. Long events up to 5000 16-bit words are expected. Most data acquisition systems were converted to the new format in the early eighties.
PROGRAM EPTEST(TAPE10,OUTPUT)
DIMENSION IBUF(512),IRECI(5000)
CALL EPINIT
C SET STATUS WORDS FOR INPUT
CALL EPSETW(10,1,1920,IERR)
IF(IERR.NE.0)STOP 1
CALL EPSETW(10,2,5000,IERR)
IF(IERR.NE.0)STOP 2
C SUPPRESS BYTE SWAPPING
CALL EPSETW(10,27,0,IERR)
IF(IERR.NE.0)STOP 3
C THE FOLLOWING CALL IS OPTIONAL; USEFUL TO VERIFY OPTIONS
CALL EPSTAT
C READ A RECORD, UNPACK AS 16-BIT WORDS
50 CALL EPREAD(10,2,NW,IRECI,IBUF,IERR)
IF(IERR.NE.0)GOTO 500
JJ=NW-5
PRINT*,NW,(IRECI(I),I=1,5),(IRECI(I),I=JJ,NW)
GOTO 50
C READ ERRORS
C EOF
500 IF(IERR.EQ.1)STOP
C PARITY AND OTHER
GOTO 50
END
This example starts by skipping to a selected block on the input unit 10 using MODE=30 in EPREAD. Then a further selection is made on the logical record header (looking for ID=0) using MODE=20. The data for these events are then unpacked as 16-bit words, and only the first 100 words are written to the output unit (20) and packed in 32-bits. In addition a user defined header (IH) is used where IH(1-4) are the default package header, IH(5) is the original number of data words and IH(6) the original record sequence number.
PROGRAM EPTEST
DIMENSION IBUF(900),IBUFO(900),IRECI(1000),IH(6)
CALL EPINIT
C SET STATUS WORDS FOR INPUT
CALL EPSETW(10,2,1000,IERR)
IF(IERR.NE.0)STOP 1
C-- SKIP TO BLOCK 15
5 CALL EPREAD(10,30,NW,IRECI,IBUF,IERR)
IF(IERR.NE.0)STOP 5
IF(IRECI(3).LT.15)GOTO 5
C-- READ THE RECORD HEADER AND SELECT RECORDS WITH TYPE ID=0
50 CALL EPREAD(10,20,NW,IRECI,IBUF,IERR)
IF(IERR.NE.0)GOTO 500
IF(IRECI(2).NE.0)GOTO 50
IH(6)=IRECI(4)
C-- READ DATA OF CURRENT RECORD, UNPACK AS 16-BIT WORDS
CALL EPREAD(10,12,NW,IRECI,IBUF,IERR)
IF(IERR.NE.0)GOTO 500
JJ=NW-4
PRINT*,NW,(IRECI(I),I=1,5),(IRECI(I),I=JJ,NW)
IH(5)=NW
C-- WRITE AS 32-BIT WORDS
CALL EPOUTL(20,3,6,IH,100,IRECI,IBUFO,IERR)
IF(IERR.NE.0)GOTO 600
GOTO 50
C READ ERRORS
C PARITY AND OTHER
500 IF(IERR.NE.1)GOTO 50
C EOF
CALL EPCLOS(20,IBUFO,IERR)
STOP
C WRITE ERRORS
600 STOP 600
END
This example also shows the control language to run in VM/CMS.
/* Test 32 bit headers */
'exec cernlib'
'vfort out32 (noprint '
'filedef iofile20 disk out32 data a4 ( recfm u lrecl 32400 block 32400'
'load out32 ( start '
'erase load map '
'erase out32 text a1'
/*BEGIN OUT32 FORTRAN A3 */
DIMENSION IBUF(8100),A(50000)
CALL EPINIT
CALL EPSETW(20, 1,16200,IERR)
CALL EPSETW(20, 2,100000,IERR)
CALL EPSETW(20, 3, 32 ,IERR)
CALL EPSETW(20,29, 1 ,IERR)
C OUTPUT 4 long LOGICAL RECORDS
C
DO 10 I=1,4
NW=10000 * (I+1)
CALL USER(A,NW,I)
C .................................................
C ROUTINE -USER- HAS STORED NW VALUES IN A TO BE WRITTEN OUT.
C .........................................
CALL EPOUTS(20,3,NW,A,IBUF,IERR)
C IF(IERR.NE.0)STOP 1
10 CONTINUE
C++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
C
C THE FOLLOWING CALL IS ESSENTIAL
C
C++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
CALL EPCLOS(20,IBUF,IERR)
C .........................................................
C FOLLOWING CALL ONLY NECESSARY ON SOME COMPUTERS (UNIVAC,IBM)
C ON VM (AND MVS?) WE THINK THIS SHOULD BE EPRWND(20,IBUF,IERR)
C WITH APPROPRIATE FILEDEF (IODD IN MVS)
C .........................................................
C CALL EPEND(20,IBUF,IERR)
CALL EPRWND(20,IBUF,IERR)
IF(IERR.NE.0)STOP 2
STOP
END
SUBROUTINE USER(A,NW,I)
INTEGER A(1)
DO 10 J=1,NW
A(J)=I
10 CONTINUE
RETURN
END