float_t OperationNaiveEvalHessianModFundamentalSpline::evalHessian(
const DataVector& alpha, const DataVector& point,
DataVector& gradient, DataMatrix& hessian) {
const size_t n = storage->size();
const size_t d = storage->dim();
float_t result = 0.0;
gradient.resize(storage->dim());
gradient.setAll(0.0);
hessian = DataMatrix(d, d);
hessian.setAll(0.0);
DataVector curGradient(d);
DataMatrix curHessian(d, d);
for (size_t i = 0; i < n; i++) {
const GridIndex& gp = *(*storage)[i];
float_t curValue = 1.0;
curGradient.setAll(alpha[i]);
curHessian.setAll(alpha[i]);
for (size_t t = 0; t < d; t++) {
const float_t val1d = base.eval(gp.getLevel(t), gp.getIndex(t), point[t]);
const float_t dx1d = base.evalDx(gp.getLevel(t), gp.getIndex(t),
point[t]);
const float_t dxdx1d = base.evalDxDx(gp.getLevel(t), gp.getIndex(t), point[t]);
curValue *= val1d;
for (size_t t2 = 0; t2 < d; t2++) {
if (t2 == t) {
curGradient[t2] *= dx1d;
for (size_t t3 = 0; t3 < d; t3++) {
if (t3 == t) {
curHessian(t2, t3) *= dxdx1d;
} else {
curHessian(t2, t3) *= dx1d;
}
}
} else {
curGradient[t2] *= val1d;
for (size_t t3 = 0; t3 < d; t3++) {
if (t3 == t) {
curHessian(t2, t3) *= dx1d;
} else {
curHessian(t2, t3) *= val1d;
}
}
}
}
}
result += alpha[i] * curValue;
gradient.add(curGradient);
hessian.add(curHessian);
}
return result;
}
