void CStreamingSparseFeatures<T>::expand_if_required(float64_t*& vec, int32_t &len)
{
int32_t dim = get_dim_feature_space();
if (dim > len)
{
vec = SG_REALLOC(float64_t, vec, len, dim);
memset(&vec[len], 0, (dim-len) * sizeof(float64_t));
len = dim;
}
}
float64_t CRandomKitchenSinksDotFeatures::dense_dot(
int32_t vec_idx1, const float64_t* vec2, int32_t vec2_len)
{
SG_DEBUG("entering dense_dot()\n");
ASSERT(vec2_len == get_dim_feature_space());
float64_t dot_product = 0;
for (index_t i=0; i<num_samples; i++)
{
float64_t tmp_dot = dot(vec_idx1, i);
tmp_dot = post_dot(tmp_dot, i);
dot_product += tmp_dot * vec2[i];
}
SG_DEBUG("Leaving dense_dot()\n");
return dot_product;
}
void CRandomKitchenSinksDotFeatures::add_to_dense_vec(float64_t alpha,
int32_t vec_idx1, float64_t* vec2, int32_t vec2_len, bool abs_val)
{
SG_DEBUG("Entering add_to_dense()\n");
ASSERT(vec2_len == get_dim_feature_space());
for (index_t i=0; i<num_samples; i++)
{
float64_t tmp_dot = dot(vec_idx1, i);
tmp_dot = post_dot(tmp_dot, i);
if (abs_val)
vec2[i] += CMath::abs(alpha * tmp_dot);
else
vec2[i] += alpha * tmp_dot;
}
SG_DEBUG("Leaving add_to_dense()\n");
}
float64_t CRandomKitchenSinksDotFeatures::dot(int32_t vec_idx1, CDotFeatures* df,
int32_t vec_idx2)
{
ASSERT(typeid(*this) == typeid(*df));
CRandomKitchenSinksDotFeatures* other = (CRandomKitchenSinksDotFeatures* ) df;
ASSERT(get_dim_feature_space()==other->get_dim_feature_space());
float64_t dot_product = 0;
for (index_t i=0; i<num_samples; i++)
{
float64_t tmp_dot_1 = dot(vec_idx1, i);
float64_t tmp_dot_2 = other->dot(vec_idx2, i);
tmp_dot_1 = post_dot(tmp_dot_1, i);
tmp_dot_2 = other->post_dot(tmp_dot_2, i);
dot_product += tmp_dot_1 * tmp_dot_2;
}
return dot_product;
}
