// Gradient computations
double DenseCRF::gradient( int n_iterations, const ObjectiveFunction & objective, VectorXf * unary_grad, VectorXf * lbl_cmp_grad, VectorXf * kernel_grad) const {
// Run inference
std::vector< MatrixXf > Q(n_iterations+1);
MatrixXf tmp1, unary( M_, N_ ), tmp2;
unary.fill(0);
if( unary_ )
unary = unary_->get();
expAndNormalize( Q[0], -unary );
for( int it=0; it<n_iterations; it++ ) {
tmp1 = -unary;
for( unsigned int k=0; k<pairwise_.size(); k++ ) {
pairwise_[k]->apply( tmp2, Q[it] );
tmp1 -= tmp2;
}
expAndNormalize( Q[it+1], tmp1 );
}
// Compute the objective value
MatrixXf b( M_, N_ );
double r = objective.evaluate( b, Q[n_iterations] );
sumAndNormalize( b, b, Q[n_iterations] );
// Compute the gradient
if(unary_grad && unary_)
*unary_grad = unary_->gradient( b );
if( lbl_cmp_grad )
*lbl_cmp_grad = 0*labelCompatibilityParameters();
if( kernel_grad )
*kernel_grad = 0*kernelParameters();
for( int it=n_iterations-1; it>=0; it-- ) {
// Do the inverse message passing
tmp1.fill(0);
int ip = 0, ik = 0;
// Add up all pairwise potentials
for( unsigned int k=0; k<pairwise_.size(); k++ ) {
// Compute the pairwise gradient expression
if( lbl_cmp_grad ) {
VectorXf pg = pairwise_[k]->gradient( b, Q[it] );
lbl_cmp_grad->segment( ip, pg.rows() ) += pg;
ip += pg.rows();
}
// Compute the kernel gradient expression
if( kernel_grad ) {
VectorXf pg = pairwise_[k]->kernelGradient( b, Q[it] );
kernel_grad->segment( ik, pg.rows() ) += pg;
ik += pg.rows();
}
// Compute the new b
pairwise_[k]->applyTranspose( tmp2, b );
tmp1 += tmp2;
}
sumAndNormalize( b, tmp1.array()*Q[it].array(), Q[it] );
// Add the gradient
if(unary_grad && unary_)
*unary_grad += unary_->gradient( b );
}
return r;
}
void testSaxpyAndSquarenormEvenOdd(const LatticeExtents lE, const hmc_complex cN)
{
SaxpyAndSquarenormEvenOddTestParameters parametersForThisTest{lE, cN};
hardware::HardwareParametersMockup hardwareParameters(parametersForThisTest.ns, parametersForThisTest.nt, true);
hardware::code::OpenClKernelParametersMockupForMergedSpinorKernels kernelParameters(parametersForThisTest.ns,
parametersForThisTest.nt);
ParameterCollection parameterCollection{hardwareParameters, kernelParameters};
SaxpyAndSquarenormEvenOddTester(parameterCollection, parametersForThisTest);
}
