Procedure

     DCBRT ( Double precision cube root )

     DOUBLE PRECISION FUNCTION  DCBRT ( X )

Abstract

     Return the cube root of a double precision number.

Required_Reading

     None.

Keywords

     MATH
     ROOT

Declarations

     IMPLICIT NONE

     DOUBLE PRECISION   X

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     X          I     Number whose cube root is desired.

     The function returns the cube root of the input value.

Detailed_Input

     X        is a double precision value.

Detailed_Output

     The function returns the cube root of the input value.

Parameters

     None.

Exceptions

     Error free.

Files

     None.

Particulars

     DCBRT calculates the cube root of the input value by using the
     exponentiation operator to raise the input value to the 1/3
     power. This operation, however, is performed on the absolute
     value of the input variable, and then the sign of the input
     is transferred to the output value.

     All values of the input variable X should be acceptable to the
     DCBRT.

Examples

     The following table gives sample values of the variable X and
     DCBRT(X)

      X                        DCBRT(X)
     --------------------------------------------------------------
      0.0D0                    0.0D0
      8.0D0                    2.0D0
     -1.0D3                   -1.0D1

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     W.M. Owen          (JPL)
     W.L. Taber         (JPL)

Version

    SPICELIB Version 1.1.0, 17-JUN-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.0.1, 10-MAR-1992 (WLT)

        Comment section for permuted index source lines was added
        following the header.

    SPICELIB Version 1.0.0, 31-JAN-1990 (WMO)