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C++ Vector::nrow方法代码示例

本文整理汇总了C++中simtk::Vector::nrow方法的典型用法代码示例。如果您正苦于以下问题:C++ Vector::nrow方法的具体用法?C++ Vector::nrow怎么用?C++ Vector::nrow使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在simtk::Vector的用法示例。


在下文中一共展示了Vector::nrow方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: log

/*Detailed Computational Costs
                Comparisons     Div     Mult     Additions   Assignments
    splineGuess log(n,2)                2        3           1
    (n currently set to 100)

    Newton Iter
        f                               21       20          13 
        df                              20       19          11
        update  4               1                3           6    
        total   4               1       41       42          30
    \endverbatim

    To evaluate u to SimTK::Eps*100 this typically involves 2 Newton 
    iterations, yielding a total cost of

    \verbatim
                Comparisons     Div     Mult    Additions   Assignments
    eval U      7+8=15          2       82      42          60
*/
double SegmentedQuinticBezierToolkit::calcU(double ax, const SimTK::Vector& bezierPtsX, 
                                 const SimTK::Spline& splineUX, double tol, 
                                 int maxIter)
{
    //Check to make sure that ax is in the curve domain
    double minX = 1e100;
    double maxX = -1e100;
    for(int i=0; i<bezierPtsX.nrow(); i++){
        if(bezierPtsX(i) > maxX)
            maxX = bezierPtsX(i);
        if(bezierPtsX(i) < minX)
            minX = bezierPtsX(i);
    }

    SimTK_ERRCHK_ALWAYS( ax >= minX && ax <= maxX, 
        "SegmentedQuinticBezierToolkit::calcU", 
        "Error: input ax was not in the domain of the Bezier curve specified \n"
        "by the control points in bezierPtsX.");

    double u = splineUX.calcValue(ax);
    u = clampU(u);
    double f = 0;


    f = calcQuinticBezierCurveVal(u,bezierPtsX)-ax;
    double df= 0;
    double du= 0;
    int iter = 0;
    bool pathologic = false;
    
    //Newton iterate to the desired tolerance
    while(abs(f) > tol && iter < maxIter && pathologic == false){
       //Take a Newton step
        df = calcQuinticBezierCurveDerivU(u,bezierPtsX,1);
        if(abs(df) > 0){
            du = -f/df;
            u  = u + du;
            u  = clampU(u); 
            f = calcQuinticBezierCurveVal(u,bezierPtsX)-ax;
        }else{
            pathologic = true;
        }
        iter++;
    }

    //Check for convergence
    SimTK_ERRCHK2_ALWAYS( (f <= tol), 
        "SegmentedQuinticBezierToolkit::calcU", 
        "Error: desired tolerance of %f on U not met by the Newton iteration."
        " A tolerance of %f was reached.",tol, f);

    SimTK_ERRCHK_ALWAYS( (pathologic==false), 
        "SegmentedQuinticBezierToolkit::calcU", 
        "Error: Newton iteration went pathologic: df = 0 to machine precision.");
      
    
    //Return the value
    return u;
}
开发者ID:ANKELA,项目名称:opensim-core,代码行数:78,代码来源:SegmentedQuinticBezierToolkit.cpp


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