# dxc210.f

          SUBROUTINE DXC210 (K, Z, J, IERROR)
    C***BEGIN PROLOGUE  DXC210
    C***PURPOSE  To provide double-precision floating-point arithmetic
    C            with an extended exponent range.
    C***LIBRARY   SLATEC
    C***CATEGORY  A3D
    C***TYPE      DOUBLE PRECISION (XC210-S, DXC210-D)
    C***KEYWORDS  EXTENDED-RANGE DOUBLE-PRECISION ARITHMETIC
    C***AUTHOR  Lozier, Daniel W., (National Bureau of Standards)
    C           Smith, John M., (NBS and George Mason University)
    C***DESCRIPTION
    C     INTEGER K, J
    C     DOUBLE PRECISION Z
    C
    C                  GIVEN K THIS SUBROUTINE COMPUTES J AND Z
    C                  SUCH THAT  RADIX**K = Z*10**J, WHERE Z IS IN
    C                  THE RANGE 1/10 .LE. Z .LT. 1.
    C                  THE VALUE OF Z WILL BE ACCURATE TO FULL
    C                  DOUBLE-PRECISION PROVIDED THE NUMBER
    C                  OF DECIMAL PLACES IN THE LARGEST
    C                  INTEGER PLUS THE NUMBER OF DECIMAL
    C                  PLACES CARRIED IN DOUBLE-PRECISION DOES NOT
    C                  EXCEED 60. DXC210 IS CALLED BY SUBROUTINE
    C                  DXCON WHEN NECESSARY. THE USER SHOULD
    C                  NEVER NEED TO CALL DXC210 DIRECTLY.
    C
    C***SEE ALSO  DXSET
    C***REFERENCES  (NONE)
    C***ROUTINES CALLED  XERMSG
    C***COMMON BLOCKS    DXBLK3
    C***REVISION HISTORY  (YYMMDD)
    C   820712  DATE WRITTEN
    C   890126  Revised to meet SLATEC CML recommendations.  (DWL and JMS)
    C   901019  Revisions to prologue.  (DWL and WRB)
    C   901106  Changed all specific intrinsics to generic.  (WRB)
    C           Corrected order of sections in prologue and added TYPE
    C           section.  (WRB)
    C           CALLs to XERROR changed to CALLs to XERMSG.  (WRB)
    C   920127  Revised PURPOSE section of prologue.  (DWL)
    C***END PROLOGUE  DXC210