TABLE OF CONTENTS

CcurveUpdate/FrailtySplineVar [ Functions ]

NAME

    FrailtySplineVar --- compute frailty variance of a spline component

FUNCTION

For the spline component of a frailty density curve, compute the corresponding frailty variance.

SYNOPSIS

664 double FrailtySplineVar(curveP frailty)

INPUTS

    frailty   a frailty CCurve

OUTPUTS

    fvar      variance of the frailty density

SOURCE

668 {
669     double fvar=0;
670     double * Moment2 = (double *) malloc( frailty->nj * sizeof(double));
671     int ord = frailty->SplineOrd;
672     int K = frailty->SplineNknots;
673     int N=2;
674     // vector of second moments of each basis function
675     cevalEinte(Moment2,frailty->SplineKnots,&ord,&K,&N);
676     for(int i=0;i<frailty->nj;i++) Moment2[i] = 1-Moment2[i];
677     // second moment of the entire density
678     fvar = ddotWrapper(frailty->nj, Moment2, frailty->SplineEPar)/frailty->SplineEParSum;
679     // subtract mean^2
680     fvar = fvar - 1.0;
681     return fvar;
682 }