SLATEC Routines --- DX4 ---

*DECK DX4
      SUBROUTINE DX4 (U, IDMN, I, J, UXXX, UXXXX)
C***BEGIN PROLOGUE  DX4
C***SUBSIDIARY
C***PURPOSE  Subsidiary to SEPX4
C***LIBRARY   SLATEC
C***TYPE      SINGLE PRECISION (DX4-S)
C***AUTHOR  (UNKNOWN)
C***DESCRIPTION
C
C     This program computes second order finite difference
C     approximations to the third and fourth X
C     partial derivatives of U at the (I,J) mesh point.
C
C***SEE ALSO  SEPX4
C***ROUTINES CALLED  (NONE)
C***COMMON BLOCKS    SPL4
C***REVISION HISTORY  (YYMMDD)
C   801001  DATE WRITTEN
C   891214  Prologue converted to Version 4.0 format.  (BAB)
C   900402  Added TYPE section.  (WRB)
C***END PROLOGUE  DX4