CHEBY
The CHEBY subroutine evaluates a Chebyshev polynomial.
Use
Called By
Any user-written subroutine
Prerequisites
None
Calling Sequence
CALL CHEBY (x, x0, par, npar, iord, value, errflg)
Input Arguments
x | A double-precision variable that specifies the independent variable. |
x0 | A double-precision variable that specifies a shift in the Chebyshev polynomial. |
par | A double-precision array of coefficients (a0,...,an). |
npar | An integer variable that specifies the number of coefficients specified. |
iord | An integer variable that specifies the order of the derivative that CHEBY is to return. IORD can be zero, one, or two. |
Output Arguments
value | A double-precision value the subroutine returns. The table below summarizes the value it returns:  | |
errflg | A logical (true or false) variable that CHEBY returns to the calling subroutine. If CHEBY detects an error in the subroutine call statement, it sets errflg to true before it returns errflg to the calling subroutine. | |
Extended Definition
CHEBY evaluates a Chebyshev polynomial. The following equation defines CHEBY:
where:
and:
