CAMLprim value ml_gsl_blas_sger(value alpha, value X, value Y, value A)
{
_DECLARE_MATRIX(A);
_DECLARE_VECTOR2(X, Y);
_CONVERT_MATRIX(A);
_CONVERT_VECTOR2(X, Y);
gsl_blas_sger(Double_val(alpha), &v_X, &v_Y, &m_A);
return Val_unit;
}
// We need to compute something like:
// sum_{k != i, j} \lambda_{i,k} x_i q_k(x_k = 1)
// = x_i (\sum \lambda_{i, k} q_k(x_k = 1) -
// \lambda_{i, j} q_j(x_j = 0))
// (note that lambda_{i, i} = 0)
unsigned int estimateExpectations() {
// estimates_{x,y} = lambda_{x,y}
gsl_matrix_float_memcpy(estimates_, lambda_);
// estimates_{x,y} = lambda_{x,y} + kappa_x
gsl_blas_sger(1.0, ones_, kappa_, estimates_);
// estimates_{x,y} = lambda_{x,y} + kappa_x + kappa_y
gsl_blas_sger(1.0, kappa_, ones_, estimates_);
gsl_vector_float_set_zero(q_lambda_);
gsl_blas_sgemv(CblasNoTrans,
1.0,
lambda_,
singleton_expectation_,
1.0,
q_lambda_);
// estimates_{x,y} = lambda_{x,y} + kappa_x + kappa_y
// + E_q [ sum lambda_{x, z} + lambda_{z, y} ]
gsl_blas_sger(1.0, ones_, q_lambda_, estimates_);
gsl_blas_sger(1.0, q_lambda_, ones_, estimates_);
}
/**
* C++ version of gsl_blas_sger().
* @param alpha A constant
* @param X A vector
* @param Y A vector
* @param A A matrix
* @return Error code on failure
*/
int sger( float alpha, vector_float const& X, vector_float const& Y, matrix_float& A ){
return gsl_blas_sger( alpha, X.get(), Y.get(), A.get() ); }
