GTCURV
GTCURV evaluates a B-spline or user-written curve created by a CURVE statement (C++ or FORTRAN).
Use
Called By
Any user-written subroutine
Prerequisite
CURVE statement in the dataset
Calling Sequence
CALL GTCURV (id, alpha, iord, array, istat)
Input Arguments
id | An integer variable that specifies the ID of the corresponding CURVE statement. |
alpha | A double-precision variable that identifies the value of the independent parameter, a, at which GTCURV is to evaluate the curve. If the curve is a B-spline computed by the CURVE statement, alpha must be in the domain -1 < alpha < 1. If the curve is computed by CURSUB, alpha must be in the domain MINPAR < alpha < MAXPAR (these are specified in the CURVE statement). |
iord | An integer variable that specifies the order of the derivative the GTCURV is to return. The legal values are: ■0 - Returns the curve coordinate. ■1 - Returns the first derivative with respect to  . ■2 - Returns the second derivative with respect to  . |
Output Arguments
array | A double-precision array of length three which contains the returned values of x, y, z.  |
istat | An integer variable that indicates either the success or teason for the failure of the call to GTCURV.  |
Extended Definition
GTCURV evaluates a B-spline or a user-written curve defined by a CURVE statements and returns one of the following:
■A value for the dependent variables (x, y, z) for each value it receives for alpha.
■The first partial derivatives of the dependent variable.
■The second partial derivatives of the dependent variable.