CUBSPL

Utility/Data Access SubroutineUses the cubic spline fitting method to return the interpolated value or n-th derivative of the interpolated value for a Reference_Spline element.

Use

The function can be called by any user-defined subroutine.

Format

Fortran Calling Syntax
CALL CUBSPL (XVAL, ZVAL, ID, IORD, ARRAY, ERRFLG)
C/C++ Calling Syntax
c_cubspl(xval, zval, id, iord, array, errflg)
Python Calling Syntax
[value, eflag] = py_cubspl(x, z, id, iord)
MATLAB Calling Syntax
[value, eflag] = m_cubspl(x, z, id, iord)

Attributes

ID
[integer]
The identifier of the corresponding user defined Reference_Spline element.
xval
[double precision]
The independent x value at which the cubic spline function is supposed to interpolate the output value.
ZVAL
[double precision]
The independent z value at which the cubic spline function is supposed to interpolate the output value for a 3-D spline data.
IORD
[logical]
The order of derivative returned by the CUBSPL function.

Output

ARRAY
[double precision]
The vector output value of dimension 3 that contains the computed interpolated value y (for IORD equal to 0).
If IORD is 1, then the returned values are the derivatives of y with respect to x and z.
If IORD is 2, then the output arrays contains the second derivatives of dy in dx2, dxdz, and dz2, respectively.
ERRFLG
[logical]
The logical variable that is returned to the calling subroutine and that indicates the success of the CUBSPL function call.