      DOUBLE PRECISION FUNCTION D1MACH(I)
      INTEGER 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
C  FOR IEEE-ARITHMETIC MACHINES (BINARY STANDARD), ONE OF THE FIRST
C  TWO SETS OF CONSTANTS BELOW SHOULD BE APPROPRIATE.
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
      INTEGER SMALL(2)
      INTEGER LARGE(2)
      INTEGER RIGHT(2)
      INTEGER DIVER(2)
      INTEGER LOG10(2)
      INTEGER SC
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 IEEE ARITHMETIC MACHINES, SUCH AS THE AT&T
C     3B SERIES AND MOTOROLA 68000 BASED MACHINES (E.G. SUN 3 AND AT&T
C     PC 7300), IN WHICH THE MOST SIGNIFICANT BYTE IS STORED FIRST.
C     
      DATA SMALL(1),SMALL(2) /    1048576,          0 /
      DATA LARGE(1),LARGE(2) / 2146435071,         -1 /
      DATA RIGHT(1),RIGHT(2) / 1017118720,          0 /
      DATA DIVER(1),DIVER(2) / 1018167296,          0 /
      DATA LOG10(1),LOG10(2) / 1070810131, 1352628735 /, SC/987/
C
C     MACHINE CONSTANTS FOR IEEE ARITHMETIC MACHINES AND 8087-BASED
C     MICROS, SUCH AS THE IBM PC AND AT&T 6300, IN WHICH THE LEAST
C     SIGNIFICANT BYTE IS STORED FIRST.
C
C      DATA SMALL(1),SMALL(2) /          0,    1048576 /
C      DATA LARGE(1),LARGE(2) /         -1, 2146435071 /
C      DATA RIGHT(1),RIGHT(2) /          0, 1017118720 /
C      DATA DIVER(1),DIVER(2) /          0, 1018167296 /
C      DATA LOG10(1),LOG10(2) / 1352628735, 1070810131 /, SC/987/
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     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      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...
      IF (SC .NE. 987) STOP 779
C/6S
C     IF (I .LT. 1  .OR.  I .GT. 5)
C    1   CALL SETERR(24HD1MACH - I OUT OF BOUNDS,24,1,2)
C/7S
C
      D1MACH = DMACH(I)
      RETURN
C
      END
