TABLE OF CONTENTS

CcurveUpdate/UpdateSplinePar [ Functions ]

NAME

    UpdateSplinePar --- update the spline parameters

FUNCTION

Function called to update the spline parameters in a CCurve. It copies a set of new parameters into the curve and re-evaluates the curve appropriately.

SYNOPSIS

1314 void UpdateSplinePar(curveP theCurve, double * newpar, int j)

INPUTS

    theCurve      a CCurve structure whose spline parameters should be updated
    newpar        new spline parameters
    j             index of single parameter to be updated (or -1 for all)

OUTPUTS

    theCurve      CCurve with updated Y and Ycum

SOURCE

1318 {
1319     if(!theCurve->hasSpline) return;
1320     if(j>=0){
1321         // updateSplinePar can only be called with j>0 for hazard curve
1322         if(!theCurve->isHazard) Rprintf("Bad call to UpdateSplinePar\n");
1323         double oldeparj = theCurve->SplineEPar[j];
1324         double neweparj = exp(newpar[j]);
1325         double epardiff = neweparj - oldeparj;
1326         theCurve->SplinePar[j] = newpar[j];
1327         theCurve->SplineEPar[j] = neweparj;
1328         theCurve->SplineEParSum += epardiff;
1329         int c1 = 1;
1330         // update the curve by changing only the j-th parameter
1331         F77_CALL(daxpy)(&(theCurve->nx), &epardiff, theCurve->SplineBasis+j*theCurve->nx, &c1,
1332                 theCurve->SplineY, &c1); 
1333         if(theCurve->isHazard) F77_CALL(daxpy)(&(theCurve->nx), &epardiff,
1334                 theCurve->SplineBasisCum+j*theCurve->nx, &c1, theCurve->SplineYcum, &c1); 
1335         ReweightCurve(theCurve, -1);
1336     }else{
1337         // copy the new parameters into the curve structure
1338         dcopyWrapper(theCurve->nj, newpar, theCurve->SplinePar);
1339         // make sure that for the frailty, the parameter at the fixed index = 0
1340         if(!theCurve->isHazard) 
1341             for(int i=0;i<theCurve->nj; i++) theCurve->SplinePar[i] -= newpar[theCurve->SplineFixedInd];
1342         // compute exponentials of parameters
1343         for(int i=0; i<theCurve->nj; i++) theCurve->SplineEPar[i] = exp(theCurve->SplinePar[i]);
1344         // normalize parameters for frailty
1345         if(!theCurve->isHazard){
1346             theCurve->SplineEParSum = 0;
1347             for(int j=0; j<theCurve->nj; j++) theCurve->SplineEParSum+=theCurve->SplineEPar[j];
1348             theCurve->SplineFvar = FrailtySplineVar(theCurve);
1349         }
1350         // evaluate the spline at the new parameters
1351         EvalSpline(theCurve, -1);
1352     }
1353 }