static void copy_large_entries(const DynamicSparseVector &u, double threshhold, StaticSparseVector &v)
{
DynamicSparseVector::const_iterator p;
for(p=u.begin(); p!=u.end(); ++p){
if(std::fabs(p->value)>threshhold) v.push_back(*p);
}
}
static double vector_norm(const DynamicSparseVector &v)
{
double norm_squared=0;
DynamicSparseVector::const_iterator p;
for(p=v.begin(); p!=v.end(); ++p) norm_squared+=sqr(p->value);
return std::sqrt(norm_squared);
}
void SparseMatrixDynamicCSR::
add_sparse_row(int i, const DynamicSparseVector &x, double multiplier)
{
assert(i>=0 && i<m);
DynamicSparseVector &r=row[i];
DynamicSparseVector::iterator p=r.begin();
DynamicSparseVector::const_iterator q=x.begin();
while(p!=r.end() && q!=x.end()){
if(p->index<q->index) ++p;
else if(p->index>q->index){
r.insert(p, SparseEntry(q->index, multiplier*q->value));
++q;
}else{
p->value+=multiplier*q->value;
++p;
++q;
}
}
for(; q!=x.end(); ++q) r.push_back(SparseEntry(q->index, multiplier*q->value));
}
static double dot_product(const StaticSparseVector &u, const DynamicSparseVector &v)
{
StaticSparseVector::const_iterator p=u.begin();
if(p==u.end()) return 0;
DynamicSparseVector::const_iterator q=v.begin();
if(q==v.end()) return 0;
double result=0;
for(;;){
if(p->index < q->index){
++p; if(p==u.end()) break;
}else if(p->index > q->index){
++q; if(q==v.end()) break;
}else{ // p->index == q->index
result+=p->value*q->value;
++p; if(p==u.end()) break;
++q; if(q==v.end()) break;
}
}
return result;
}
static void add_to_vector(double multiplier, const StaticSparseVector &u, DynamicSparseVector &v)
{
StaticSparseVector::const_iterator p=u.begin();
if(p==u.end()) return;
DynamicSparseVector::iterator q=v.begin();
for(;;){
if(q==v.end()) break;
if(p->index < q->index){
q=v.insert(q, SparseEntry(p->index, multiplier*p->value));
++p; if(p==u.end()) return;
}else if(p->index > q->index){
++q; if(q==v.end()) break;
}else{ // p->index == q->index){
q->value+=multiplier*p->value;
++p; if(p==u.end()) return;
++q; if(q==v.end()) break;
}
}
for(;;){
v.push_back(SparseEntry(p->index, multiplier*p->value));
++p; if(p==u.end()) return;
}
}
static void copy_column(int colstart, int nextcolstart, const int *rowindex, const double *value,
DynamicSparseVector &v)
{
for(int i=colstart; i<nextcolstart; ++i)
v.push_back(SparseEntry(rowindex[i], value[i]));
}
