DOUBLE PRECISION FUNCTION D1MACH(I) C C DOUBLE-PRECISION MACHINE CONSTANTS C C D1MACH( 1) = B**(EMIN-1), THE SMALLEST POSITIVE MAGNITUDE. C C D1MACH( 2) = B**EMAX*(1 - B**(-T)), THE LARGEST MAGNITUDE. C C D1MACH( 3) = B**(-T), THE SMALLEST RELATIVE SPACING. C C D1MACH( 4) = B**(1-T), THE LARGEST RELATIVE SPACING. C C D1MACH( 5) = LOG10(B) C C TO ALTER THIS FUNCTION FOR A PARTICULAR ENVIRONMENT, C THE DESIRED SET OF DATA STATEMENTS SHOULD BE ACTIVATED BY C REMOVING THE C FROM COLUMN 1. C ON RARE MACHINES A STATIC STATEMENT MAY NEED TO BE ADDED. C (BUT PROBABLY MORE SYSTEMS PROHIBIT IT THAN REQUIRE IT.) C C FOR IEEE-ARITHMETIC MACHINES (BINARY STANDARD), ONE OF THE FIRST C TWO SETS OF CONSTANTS BELOW SHOULD BE APPROPRIATE. IF YOU DO NOT C KNOW WHICH SET TO USE, TRY BOTH AND SEE WHICH GIVES PLAUSIBLE C VALUES. C C WHERE POSSIBLE, DECIMAL, OCTAL OR HEXADECIMAL CONSTANTS ARE USED C TO SPECIFY THE CONSTANTS EXACTLY. SOMETIMES THIS REQUIRES USING C EQUIVALENT INTEGER ARRAYS. IF YOUR COMPILER USES HALF-WORD C INTEGERS BY DEFAULT (SOMETIMES CALLED INTEGER*2), YOU MAY NEED TO C CHANGE INTEGER TO INTEGER*4 OR OTHERWISE INSTRUCT YOUR COMPILER C TO USE FULL-WORD INTEGERS IN THE NEXT 5 DECLARATIONS. C C COMMENTS JUST BEFORE THE END STATEMENT (LINES STARTING WITH *) C GIVE C SOURCE FOR D1MACH. C INTEGER SMALL(2) INTEGER LARGE(2) INTEGER RIGHT(2) INTEGER DIVER(2) INTEGER LOG10(2) INTEGER I C/6S C/7S SAVE SMALL, LARGE, RIGHT, DIVER, LOG10 C/ DOUBLE PRECISION DMACH(5) C EQUIVALENCE (DMACH(1),SMALL(1)) EQUIVALENCE (DMACH(2),LARGE(1)) EQUIVALENCE (DMACH(3),RIGHT(1)) EQUIVALENCE (DMACH(4),DIVER(1)) EQUIVALENCE (DMACH(5),LOG10(1)) C C MACHINE CONSTANTS FOR BIG-ENDIAN IEEE ARITHMETIC (BINARY FORMAT) C MACHINES IN WHICH THE MOST SIGNIFICANT BYTE IS STORED FIRST, C SUCH AS THE AT&T 3B SERIES, MOTOROLA 68000 BASED MACHINES (E.G. C SUN 3), AND MACHINES THAT USE SPARC, HP, OR IBM RISC CHIPS. C C DATA SMALL(1),SMALL(2) / 1048576, 0 / C DATA LARGE(1),LARGE(2) / 2146435071, -1 / C DATA RIGHT(1),RIGHT(2) / 1017118720, 0 / C DATA DIVER(1),DIVER(2) / 1018167296, 0 / C DATA LOG10(1),LOG10(2) / 1070810131, 1352628735 / C C MACHINE CONSTANTS FOR LITTLE-ENDIAN (BINARY) IEEE ARITHMETIC C MACHINES IN WHICH THE LEAST SIGNIFICANT BYTE IS STORED FIRST, C E.G. IBM PCS AND OTHER MACHINES THAT USE INTEL 80X87 OR DEC C ALPHA CHIPS. C DATA SMALL(1),SMALL(2) / 0, 1048576 / DATA LARGE(1),LARGE(2) / -1, 2146435071 / DATA RIGHT(1),RIGHT(2) / 0, 1017118720 / DATA DIVER(1),DIVER(2) / 0, 1018167296 / DATA LOG10(1),LOG10(2) / 1352628735, 1070810131 / C C MACHINE CONSTANTS FOR AMDAHL MACHINES. C C DATA SMALL(1),SMALL(2) / 1048576, 0 / C DATA LARGE(1),LARGE(2) / 2147483647, -1 / C DATA RIGHT(1),RIGHT(2) / 856686592, 0 / C DATA DIVER(1),DIVER(2) / 873463808, 0 / C DATA LOG10(1),LOG10(2) / 1091781651, 1352628735 /, SC/987/ C C MACHINE CONSTANTS FOR THE BURROUGHS 1700 SYSTEM. C C DATA SMALL(1) / ZC00800000 / C DATA SMALL(2) / Z000000000 / C C DATA LARGE(1) / ZDFFFFFFFF / C DATA LARGE(2) / ZFFFFFFFFF / C C DATA RIGHT(1) / ZCC5800000 / C DATA RIGHT(2) / Z000000000 / C C DATA DIVER(1) / ZCC6800000 / C DATA DIVER(2) / Z000000000 / C C DATA LOG10(1) / ZD00E730E7 / C DATA LOG10(2) / ZC77800DC0 /, SC/987/ C C MACHINE CONSTANTS FOR THE BURROUGHS 5700 SYSTEM. C C DATA SMALL(1) / O1771000000000000 / C DATA SMALL(2) / O0000000000000000 / C C DATA LARGE(1) / O0777777777777777 / C DATA LARGE(2) / O0007777777777777 / C C DATA RIGHT(1) / O1461000000000000 / C DATA RIGHT(2) / O0000000000000000 / C C DATA DIVER(1) / O1451000000000000 / C DATA DIVER(2) / O0000000000000000 / C C DATA LOG10(1) / O1157163034761674 / C DATA LOG10(2) / O0006677466732724 /, SC/987/ C C MACHINE CONSTANTS FOR THE BURROUGHS 6700/7700 SYSTEMS. C C DATA SMALL(1) / O1771000000000000 / C DATA SMALL(2) / O7770000000000000 / C C DATA LARGE(1) / O0777777777777777 / C DATA LARGE(2) / O7777777777777777 / C C DATA RIGHT(1) / O1461000000000000 / C DATA RIGHT(2) / O0000000000000000 / C C DATA DIVER(1) / O1451000000000000 / C DATA DIVER(2) / O0000000000000000 / C C DATA LOG10(1) / O1157163034761674 / C DATA LOG10(2) / O0006677466732724 /, SC/987/ C C MACHINE CONSTANTS FOR FTN4 ON THE CDC 6000/7000 SERIES. C C DATA SMALL(1) / 00564000000000000000B / C DATA SMALL(2) / 00000000000000000000B / C C DATA LARGE(1) / 37757777777777777777B / C DATA LARGE(2) / 37157777777777777774B / C C DATA RIGHT(1) / 15624000000000000000B / C DATA RIGHT(2) / 00000000000000000000B / C C DATA DIVER(1) / 15634000000000000000B / C DATA DIVER(2) / 00000000000000000000B / C C DATA LOG10(1) / 17164642023241175717B / C DATA LOG10(2) / 16367571421742254654B /, SC/987/ C C MACHINE CONSTANTS FOR FTN5 ON THE CDC 6000/7000 SERIES. C C DATA SMALL(1) / O"00564000000000000000" / C DATA SMALL(2) / O"00000000000000000000" / C C DATA LARGE(1) / O"37757777777777777777" / C DATA LARGE(2) / O"37157777777777777774" / C C DATA RIGHT(1) / O"15624000000000000000" / C DATA RIGHT(2) / O"00000000000000000000" / C C DATA DIVER(1) / O"15634000000000000000" / C DATA DIVER(2) / O"00000000000000000000" / C C DATA LOG10(1) / O"17164642023241175717" / C DATA LOG10(2) / O"16367571421742254654" /, SC/987/ C C MACHINE CONSTANTS FOR CONVEX C-1 C C DATA SMALL(1),SMALL(2) / '00100000'X, '00000000'X / C DATA LARGE(1),LARGE(2) / '7FFFFFFF'X, 'FFFFFFFF'X / C DATA RIGHT(1),RIGHT(2) / '3CC00000'X, '00000000'X / C DATA DIVER(1),DIVER(2) / '3CD00000'X, '00000000'X / C DATA LOG10(1),LOG10(2) / '3FF34413'X, '509F79FF'X /, SC/987/ C C MACHINE CONSTANTS FOR THE CRAY 1, XMP, 2, AND 3. C C DATA SMALL(1) / 201354000000000000000B / C DATA SMALL(2) / 000000000000000000000B / C C DATA LARGE(1) / 577767777777777777777B / C DATA LARGE(2) / 000007777777777777776B / C C DATA RIGHT(1) / 376434000000000000000B / C DATA RIGHT(2) / 000000000000000000000B / C C DATA DIVER(1) / 376444000000000000000B / C DATA DIVER(2) / 000000000000000000000B / C C DATA LOG10(1) / 377774642023241175717B / C DATA LOG10(2) / 000007571421742254654B /, SC/987/ C C MACHINE CONSTANTS FOR THE DATA GENERAL ECLIPSE S/200 C C SMALL, LARGE, RIGHT, DIVER, LOG10 SHOULD BE DECLARED C INTEGER SMALL(4), LARGE(4), RIGHT(4), DIVER(4), LOG10(4) C C NOTE - IT MAY BE APPROPRIATE TO INCLUDE THE FOLLOWING LINE - C STATIC DMACH(5) C C DATA SMALL/20K,3*0/,LARGE/77777K,3*177777K/ C DATA RIGHT/31420K,3*0/,DIVER/32020K,3*0/ C DATA LOG10/40423K,42023K,50237K,74776K/, SC/987/ C C MACHINE CONSTANTS FOR THE HARRIS SLASH 6 AND SLASH 7 C C DATA SMALL(1),SMALL(2) / '20000000, '00000201 / C DATA LARGE(1),LARGE(2) / '37777777, '37777577 / C DATA RIGHT(1),RIGHT(2) / '20000000, '00000333 / C DATA DIVER(1),DIVER(2) / '20000000, '00000334 / C DATA LOG10(1),LOG10(2) / '23210115, '10237777 /, SC/987/ C C MACHINE CONSTANTS FOR THE HONEYWELL DPS 8/70 SERIES. C C DATA SMALL(1),SMALL(2) / O402400000000, O000000000000 / C DATA LARGE(1),LARGE(2) / O376777777777, O777777777777 / C DATA RIGHT(1),RIGHT(2) / O604400000000, O000000000000 / C DATA DIVER(1),DIVER(2) / O606400000000, O000000000000 / C DATA LOG10(1),LOG10(2) / O776464202324, O117571775714 /, SC/987/ C C MACHINE CONSTANTS FOR THE IBM 360/370 SERIES, C THE XEROX SIGMA 5/7/9 AND THE SEL SYSTEMS 85/86. C C DATA SMALL(1),SMALL(2) / Z00100000, Z00000000 / C DATA LARGE(1),LARGE(2) / Z7FFFFFFF, ZFFFFFFFF / C DATA RIGHT(1),RIGHT(2) / Z33100000, Z00000000 / C DATA DIVER(1),DIVER(2) / Z34100000, Z00000000 / C DATA LOG10(1),LOG10(2) / Z41134413, Z509F79FF /, SC/987/ C C MACHINE CONSTANTS FOR THE INTERDATA 8/32 C WITH THE UNIX SYSTEM FORTRAN 77 COMPILER. C C FOR THE INTERDATA FORTRAN VII COMPILER REPLACE C THE Z'S SPECIFYING HEX CONSTANTS WITH Y'S. C C DATA SMALL(1),SMALL(2) / Z'00100000', Z'00000000' / C DATA LARGE(1),LARGE(2) / Z'7EFFFFFF', Z'FFFFFFFF' / C DATA RIGHT(1),RIGHT(2) / Z'33100000', Z'00000000' / C DATA DIVER(1),DIVER(2) / Z'34100000', Z'00000000' / C DATA LOG10(1),LOG10(2) / Z'41134413', Z'509F79FF' /, SC/987/ C C MACHINE CONSTANTS FOR THE PDP-10 (KA PROCESSOR). C C DATA SMALL(1),SMALL(2) / "033400000000, "000000000000 / C DATA LARGE(1),LARGE(2) / "377777777777, "344777777777 / C DATA RIGHT(1),RIGHT(2) / "113400000000, "000000000000 / C DATA DIVER(1),DIVER(2) / "114400000000, "000000000000 / C DATA LOG10(1),LOG10(2) / "177464202324, "144117571776 /, SC/987/ C C MACHINE CONSTANTS FOR THE PDP-10 (KI PROCESSOR). C C DATA SMALL(1),SMALL(2) / "000400000000, "000000000000 / C DATA LARGE(1),LARGE(2) / "377777777777, "377777777777 / C DATA RIGHT(1),RIGHT(2) / "103400000000, "000000000000 / C DATA DIVER(1),DIVER(2) / "104400000000, "000000000000 / C DATA LOG10(1),LOG10(2) / "177464202324, "047674776746 /, SC/987/ C C MACHINE CONSTANTS FOR PDP-11 FORTRANS SUPPORTING C 32-BIT INTEGERS (EXPRESSED IN INTEGER AND OCTAL). C C DATA SMALL(1),SMALL(2) / 8388608, 0 / C DATA LARGE(1),LARGE(2) / 2147483647, -1 / C DATA RIGHT(1),RIGHT(2) / 612368384, 0 / C DATA DIVER(1),DIVER(2) / 620756992, 0 / C DATA LOG10(1),LOG10(2) / 1067065498, -2063872008 /, SC/987/ C C DATA SMALL(1),SMALL(2) / O00040000000, O00000000000 / C DATA LARGE(1),LARGE(2) / O17777777777, O37777777777 / C DATA RIGHT(1),RIGHT(2) / O04440000000, O00000000000 / C DATA DIVER(1),DIVER(2) / O04500000000, O00000000000 / C DATA LOG10(1),LOG10(2) / O07746420232, O20476747770 /, SC/987/ C C MACHINE CONSTANTS FOR PDP-11 FORTRANS SUPPORTING C 16-BIT INTEGERS (EXPRESSED IN INTEGER AND OCTAL). C C SMALL, LARGE, RIGHT, DIVER, LOG10 SHOULD BE DECLARED C INTEGER SMALL(4), LARGE(4), RIGHT(4), DIVER(4), LOG10(4) C C DATA SMALL(1),SMALL(2) / 128, 0 / C DATA SMALL(3),SMALL(4) / 0, 0 / C C DATA LARGE(1),LARGE(2) / 32767, -1 / C DATA LARGE(3),LARGE(4) / -1, -1 / C C DATA RIGHT(1),RIGHT(2) / 9344, 0 / C DATA RIGHT(3),RIGHT(4) / 0, 0 / C C DATA DIVER(1),DIVER(2) / 9472, 0 / C DATA DIVER(3),DIVER(4) / 0, 0 / C C DATA LOG10(1),LOG10(2) / 16282, 8346 / C DATA LOG10(3),LOG10(4) / -31493, -12296 /, SC/987/ C C DATA SMALL(1),SMALL(2) / O000200, O000000 / C DATA SMALL(3),SMALL(4) / O000000, O000000 / C C DATA LARGE(1),LARGE(2) / O077777, O177777 / C DATA LARGE(3),LARGE(4) / O177777, O177777 / C C DATA RIGHT(1),RIGHT(2) / O022200, O000000 / C DATA RIGHT(3),RIGHT(4) / O000000, O000000 / C C DATA DIVER(1),DIVER(2) / O022400, O000000 / C DATA DIVER(3),DIVER(4) / O000000, O000000 / C C DATA LOG10(1),LOG10(2) / O037632, O020232 / C DATA LOG10(3),LOG10(4) / O102373, O147770 /, SC/987/ C C MACHINE CONSTANTS FOR THE PRIME 50 SERIES SYSTEMS C WITH 32-BIT INTEGERS AND 64V MODE INSTRUCTIONS, C SUPPLIED BY IGOR BRAY. C C DATA SMALL(1),SMALL(2) / :10000000000, :00000100001 / C DATA LARGE(1),LARGE(2) / :17777777777, :37777677775 / C DATA RIGHT(1),RIGHT(2) / :10000000000, :00000000122 / C DATA DIVER(1),DIVER(2) / :10000000000, :00000000123 / C DATA LOG10(1),LOG10(2) / :11504046501, :07674600177 /, SC/987/ C C MACHINE CONSTANTS FOR THE SEQUENT BALANCE 8000 C C DATA SMALL(1),SMALL(2) / $00000000, $00100000 / C DATA LARGE(1),LARGE(2) / $FFFFFFFF, $7FEFFFFF / C DATA RIGHT(1),RIGHT(2) / $00000000, $3CA00000 / C DATA DIVER(1),DIVER(2) / $00000000, $3CB00000 / C DATA LOG10(1),LOG10(2) / $509F79FF, $3FD34413 /, SC/987/ C C MACHINE CONSTANTS FOR THE UNIVAC 1100 SERIES. C C DATA SMALL(1),SMALL(2) / O000040000000, O000000000000 / C DATA LARGE(1),LARGE(2) / O377777777777, O777777777777 / C DATA RIGHT(1),RIGHT(2) / O170540000000, O000000000000 / C DATA DIVER(1),DIVER(2) / O170640000000, O000000000000 / C DATA LOG10(1),LOG10(2) / O177746420232, O411757177572 /, SC/987/ C C MACHINE CONSTANTS FOR THE VAX UNIX F77 COMPILER C C DATA SMALL(1),SMALL(2) / 128, 0 / C DATA LARGE(1),LARGE(2) / -32769, -1 / C DATA RIGHT(1),RIGHT(2) / 9344, 0 / C DATA DIVER(1),DIVER(2) / 9472, 0 / C DATA LOG10(1),LOG10(2) / 546979738, -805796613 /, SC/987/ C C MACHINE CONSTANTS FOR THE VAX-11 WITH C FORTRAN IV-PLUS COMPILER C C DATA SMALL(1),SMALL(2) / Z00000080, Z00000000 / C DATA LARGE(1),LARGE(2) / ZFFFF7FFF, ZFFFFFFFF / C DATA RIGHT(1),RIGHT(2) / Z00002480, Z00000000 / C DATA DIVER(1),DIVER(2) / Z00002500, Z00000000 / C DATA LOG10(1),LOG10(2) / Z209A3F9A, ZCFF884FB /, SC/987/ C C MACHINE CONSTANTS FOR VAX/VMS VERSION 2.2 C C DATA SMALL(1),SMALL(2) / '80'X, '0'X / C DATA LARGE(1),LARGE(2) / 'FFFF7FFF'X, 'FFFFFFFF'X / C DATA RIGHT(1),RIGHT(2) / '2480'X, '0'X / C DATA DIVER(1),DIVER(2) / '2500'X, '0'X / C DATA LOG10(1),LOG10(2) / '209A3F9A'X, 'CFF884FB'X /, SC/987/ C C *** ISSUE STOP 779 IF ALL DATA STATEMENTS ARE COMMENTED... C IF (SC .NE. 987) THEN C DMACH(1) = 1.D13 C IF ( SMALL(1) .EQ. 1117925532 C * .AND. SMALL(2) .EQ. -448790528) THEN C* *** IEEE BIG ENDIAN *** C SMALL(1) = 1048576 C SMALL(2) = 0 C LARGE(1) = 2146435071 C LARGE(2) = -1 C RIGHT(1) = 1017118720 C RIGHT(2) = 0 C DIVER(1) = 1018167296 C DIVER(2) = 0 C LOG10(1) = 1070810131 C LOG10(2) = 1352628735 C ELSE IF ( SMALL(2) .EQ. 1117925532 C * .AND. SMALL(1) .EQ. -448790528) THEN C* *** IEEE LITTLE ENDIAN *** C SMALL(2) = 1048576 C SMALL(1) = 0 C LARGE(2) = 2146435071 C LARGE(1) = -1 C RIGHT(2) = 1017118720 C RIGHT(1) = 0 C DIVER(2) = 1018167296 C DIVER(1) = 0 C LOG10(2) = 1070810131 C LOG10(1) = 1352628735 C ELSE IF ( SMALL(1) .EQ. -2065213935 C * .AND. SMALL(2) .EQ. 10752) THEN C* *** VAX WITH D_FLOATING *** C SMALL(1) = 128 C SMALL(2) = 0 C LARGE(1) = -32769 C LARGE(2) = -1 C RIGHT(1) = 9344 C RIGHT(2) = 0 C DIVER(1) = 9472 C DIVER(2) = 0 C LOG10(1) = 546979738 C LOG10(2) = -805796613 C ELSE IF ( SMALL(1) .EQ. 1267827943 C * .AND. SMALL(2) .EQ. 704643072) THEN C* *** IBM MAINFRAME *** C SMALL(1) = 1048576 C SMALL(2) = 0 C LARGE(1) = 2147483647 C LARGE(2) = -1 C RIGHT(1) = 856686592 C RIGHT(2) = 0 C DIVER(1) = 873463808 C DIVER(2) = 0 C LOG10(1) = 1091781651 C LOG10(2) = 1352628735 C ELSE C WRITE(*,*)'Adjust D1MACH by uncommenting' C WRITE(*,*)'data statements appropriate for your machine.' C STOP 779 C END IF C SC = 987 C END IF C C *** ISSUE STOP 778 IF ALL DATA STATEMENTS ARE OBVIOUSLY WRONG... C IF (DMACH(4) .GE. 1.0D0) STOP 778 C*C/6S C*C IF (I .LT. 1 .OR. I .GT. 5) C*C 1 CALL SETERR(24HD1MACH - I OUT OF BOUNDS,24,1,2) C*C/7S C* IF (I .LT. 1 .OR. I .GT. 5) C* 1 CALL SETERR('D1MACH - I OUT OF BOUNDS',24,1,2) C*C/ C IF (I .LT. 1 .OR. I .GT. 5) THEN C WRITE(*,*) 'D1MACH(I): I =',I,' is out of bounds.' C STOP C END IF IF (I .LT. 1 .OR. I .GT. 5) THEN D1MACH = 0.0 RETURN END IF D1MACH = DMACH(I) RETURN C C* /* C source for D1MACH -- remove the * in column 1 */ C*#include C*#include C*#include C* C*double d1mach_(long *i) C*{ C* switch(*i){ C* case 1: return DBL_MIN; C* case 2: return DBL_MAX; C* case 3: return DBL_EPSILON/FLT_RADIX; C* case 4: return DBL_EPSILON; C* case 5: return log10(FLT_RADIX); C* } C* C* fprintf(stderr, "invalid argument: d1mach(%ld)\n", *i); C* exit(1); C* return 0; /* for compilers that complain of missing return values */ C* } END