share/minpack/fortran/dpmpar.f

   1       double precision function dpmpar(i)
   2       integer i
   3 c     **********
   4 c
   5 c     Function dpmpar
   6 c
   7 c     This function provides double precision machine parameters
   8 c     when the appropriate set of data statements is activated (by
   9 c     removing the c from column 1) and all other data statements are
  10 c     rendered inactive. Most of the parameter values were obtained
  11 c     from the corresponding Bell Laboratories Port Library function.
  12 c
  13 c     The function statement is
  14 c
  15 c       double precision function dpmpar(i)
  16 c
  17 c     where
  18 c
  19 c       i is an integer input variable set to 1, 2, or 3 which
  20 c         selects the desired machine parameter. If the machine has
  21 c         t base b digits and its smallest and largest exponents are
  22 c         emin and emax, respectively, then these parameters are
  23 c
  24 c         dpmpar(1) = b**(1 - t), the machine precision,
  25 c
  26 c         dpmpar(2) = b**(emin - 1), the smallest magnitude,
  27 c
  28 c         dpmpar(3) = b**emax*(1 - b**(-t)), the largest magnitude.
  29 c
  30 c     Argonne National Laboratory. MINPACK Project. November 1996.
  31 c     Burton S. Garbow, Kenneth E. Hillstrom, Jorge J. More'
  32 c
  33 c     **********
  34       integer mcheps(4)
  35       integer minmag(4)
  36       integer maxmag(4)
  37       double precision dmach(3)
  38 c     equivalence (dmach(1),mcheps(1))
  39 c     equivalence (dmach(2),minmag(1))
  40 c     equivalence (dmach(3),maxmag(1))
  41 c
  42 c     Machine constants for the IBM 360/370 series,
  43 c     the Amdahl 470/V6, the ICL 2900, the Itel AS/6,
  44 c     the Xerox Sigma 5/7/9 and the Sel systems 85/86.
  45 c
  46 c     data mcheps(1),mcheps(2) / z34100000, z00000000 /
  47 c     data minmag(1),minmag(2) / z00100000, z00000000 /
  48 c     data maxmag(1),maxmag(2) / z7fffffff, zffffffff /
  49 c
  50 c     Machine constants for the Honeywell 600/6000 series.
  51 c
  52 c     data mcheps(1),mcheps(2) / o606400000000, o000000000000 /
  53 c     data minmag(1),minmag(2) / o402400000000, o000000000000 /
  54 c     data maxmag(1),maxmag(2) / o376777777777, o777777777777 /
  55 c
  56 c     Machine constants for the CDC 6000/7000 series.
  57 c
  58 c     data mcheps(1) / 15614000000000000000b /
  59 c     data mcheps(2) / 15010000000000000000b /
  60 c
  61 c     data minmag(1) / 00604000000000000000b /
  62 c     data minmag(2) / 00000000000000000000b /
  63 c
  64 c     data maxmag(1) / 37767777777777777777b /
  65 c     data maxmag(2) / 37167777777777777777b /
  66 c
  67 c     Machine constants for the PDP-10 (KA processor).
  68 c
  69 c     data mcheps(1),mcheps(2) / "114400000000, "000000000000 /
  70 c     data minmag(1),minmag(2) / "033400000000, "000000000000 /
  71 c     data maxmag(1),maxmag(2) / "377777777777, "344777777777 /
  72 c
  73 c     Machine constants for the PDP-10 (KI processor).
  74 c
  75 c     data mcheps(1),mcheps(2) / "104400000000, "000000000000 /
  76 c     data minmag(1),minmag(2) / "000400000000, "000000000000 /
  77 c     data maxmag(1),maxmag(2) / "377777777777, "377777777777 /
  78 c
  79 c     Machine constants for the PDP-11.
  80 c
  81 c     data mcheps(1),mcheps(2) /   9472,      0 /
  82 c     data mcheps(3),mcheps(4) /      0,      0 /
  83 c
  84 c     data minmag(1),minmag(2) /    128,      0 /
  85 c     data minmag(3),minmag(4) /      0,      0 /
  86 c
  87 c     data maxmag(1),maxmag(2) /  32767,     -1 /
  88 c     data maxmag(3),maxmag(4) /     -1,     -1 /
  89 c
  90 c     Machine constants for the Burroughs 6700/7700 systems.
  91 c
  92 c     data mcheps(1) / o1451000000000000 /
  93 c     data mcheps(2) / o0000000000000000 /
  94 c
  95 c     data minmag(1) / o1771000000000000 /
  96 c     data minmag(2) / o7770000000000000 /
  97 c
  98 c     data maxmag(1) / o0777777777777777 /
  99 c     data maxmag(2) / o7777777777777777 /
 100 c
 101 c     Machine constants for the Burroughs 5700 system.
 102 c
 103 c     data mcheps(1) / o1451000000000000 /
 104 c     data mcheps(2) / o0000000000000000 /
 105 c
 106 c     data minmag(1) / o1771000000000000 /
 107 c     data minmag(2) / o0000000000000000 /
 108 c
 109 c     data maxmag(1) / o0777777777777777 /
 110 c     data maxmag(2) / o0007777777777777 /
 111 c
 112 c     Machine constants for the Burroughs 1700 system.
 113 c
 114 c     data mcheps(1) / zcc6800000 /
 115 c     data mcheps(2) / z000000000 /
 116 c
 117 c     data minmag(1) / zc00800000 /
 118 c     data minmag(2) / z000000000 /
 119 c
 120 c     data maxmag(1) / zdffffffff /
 121 c     data maxmag(2) / zfffffffff /
 122 c
 123 c     Machine constants for the Univac 1100 series.
 124 c
 125 c     data mcheps(1),mcheps(2) / o170640000000, o000000000000 /
 126 c     data minmag(1),minmag(2) / o000040000000, o000000000000 /
 127 c     data maxmag(1),maxmag(2) / o377777777777, o777777777777 /
 128 c
 129 c     Machine constants for the Data General Eclipse S/200.
 130 c
 131 c     Note - it may be appropriate to include the following card -
 132 c     static dmach(3)
 133 c
 134 c     data minmag/20k,3*0/,maxmag/77777k,3*177777k/
 135 c     data mcheps/32020k,3*0/
 136 c
 137 c     Machine constants for the Harris 220.
 138 c
 139 c     data mcheps(1),mcheps(2) / '20000000, '00000334 /
 140 c     data minmag(1),minmag(2) / '20000000, '00000201 /
 141 c     data maxmag(1),maxmag(2) / '37777777, '37777577 /
 142 c
 143 c     Machine constants for the Cray-1.
 144 c
 145 c     data mcheps(1) / 0376424000000000000000b /
 146 c     data mcheps(2) / 0000000000000000000000b /
 147 c
 148 c     data minmag(1) / 0200034000000000000000b /
 149 c     data minmag(2) / 0000000000000000000000b /
 150 c
 151 c     data maxmag(1) / 0577777777777777777777b /
 152 c     data maxmag(2) / 0000007777777777777776b /
 153 c
 154 c     Machine constants for the Prime 400.
 155 c
 156 c     data mcheps(1),mcheps(2) / :10000000000, :00000000123 /
 157 c     data minmag(1),minmag(2) / :10000000000, :00000100000 /
 158 c     data maxmag(1),maxmag(2) / :17777777777, :37777677776 /
 159 c
 160 c     Machine constants for the VAX-11.
 161 c
 162 c     data mcheps(1),mcheps(2) /   9472,  0 /
 163 c     data minmag(1),minmag(2) /    128,  0 /
 164 c     data maxmag(1),maxmag(2) / -32769, -1 /
 165 c
 166 c     Machine constants for IEEE machines.
 167 c
 168       data dmach(1) /2.22044604926d-16/
 169       data dmach(2) /2.22507385852d-308/
 170       data dmach(3) /1.79769313485d+308/
 171 c
 172       dpmpar = dmach(i)
 173       return
 174 c
 175 c     Last card of function dpmpar.
 176 c
 177       end