TABLE OF CONTENTS

CcurveUpdate/EvalSplineAtOnePoint [ Functions ]

NAME

    EvalSplineAtOnePoint --- evaluate spline at a given value of x

FUNCTION

Evaluate a spline curve at a given point, even if that point is not stored in its X component and has not been included in its basis. This differs from EvalSpline in that the latter must already have a fully computed basis stored. This one does a full curve evaluation -- in that sense it acts as a wrapper to csplineeval.

SYNOPSIS

1276 double EvalSplineAtOnePoint(curveP theCurve, double x)

INPUTS

    theCurve      a CCurve structure

OUTPUTS

    x             value at which to evaluate the spline

SOURCE

1280 {
1281     double splY=0;
1282     int c1=1;
1283     if(theCurve->hasSpline){
1284         // compute the basis at x
1285         double * tempBasis = (double *) malloc( theCurve->nj * sizeof(double));
1286         for(int j=0; j<theCurve->nj; j++) tempBasis[j]=csplineeval(x, j, theCurve->SplineOrd,
1287                 theCurve->SplineKnots, theCurve->SplineOrd, theCurve->nj);
1288         // normalize the frailty basis
1289         if(!theCurve->isHazard)
1290             for(int j=0; j<theCurve->nj; j++) tempBasis[j] /= (theCurve->SplineBasisInt[j] *
1291                     theCurve->SplineEParSum); 
1292         // compute the spline value at X
1293         splY = F77_CALL(ddot)( &(theCurve->nj), tempBasis, &c1, theCurve->SplineEPar, &c1);
1294         free(tempBasis);
1295     }
1296     return splY;
1297 }