Block compressed Lanczos

lib/algorithms/iterative/BlockImplicitlyRestartedLanczos/FieldBasisVector.h

@@ -0,0 +1,163 @@
+namespace Grid { 
+
+template<class Field>
+class BasisFieldVector {
+ public:
+  int _Nm;
+
+  typedef typename Field::scalar_type Coeff_t;
+  typedef typename Field::vector_type vCoeff_t;
+  typedef typename Field::vector_object vobj;
+  typedef typename vobj::scalar_object sobj;
+
+  std::vector<Field> _v; // _Nfull vectors
+
+  void report(int n,GridBase* value) {
+
+    std::cout << GridLogMessage << "BasisFieldVector allocated:\n";
+    std::cout << GridLogMessage << " Delta N = " << n << "\n";
+    std::cout << GridLogMessage << " Size of full vectors (size) = " << 
+      ((double)n*sizeof(vobj)*value->oSites() / 1024./1024./1024.) << " GB\n";
+    std::cout << GridLogMessage << " Size = " << _v.size() << " Capacity = " << _v.capacity() << std::endl;
+
+    value->Barrier();
+
+    if (value->IsBoss()) {
+      system("cat /proc/meminfo");
+    }
+
+    value->Barrier();
+
+  }
+
+  BasisFieldVector(int Nm,GridBase* value) : _Nm(Nm), _v(Nm,value) {
+    report(Nm,value);
+  }
+  
+  ~BasisFieldVector() {
+  }
+
+  Field& operator[](int i) {
+    return _v[i];
+  }
+
+  void orthogonalize(Field& w, int k) {
+    for(int j=0; j<k; ++j){
+      Coeff_t ip = (Coeff_t)innerProduct(_v[j],w);
+      w = w - ip*_v[j];
+    }
+  }
+
+  void rotate(std::vector<RealD>& Qt,int j0, int j1, int k0,int k1,int Nm) {
+    
+    GridBase* grid = _v[0]._grid;
+      
+#pragma omp parallel
+    {
+      std::vector < vobj > B(Nm);
+      
+#pragma omp for
+      for(int ss=0;ss < grid->oSites();ss++){
+	for(int j=j0; j<j1; ++j) B[j]=0.;
+	
+	for(int j=j0; j<j1; ++j){
+	  for(int k=k0; k<k1; ++k){
+	    B[j] +=Qt[k+Nm*j] * _v[k]._odata[ss];
+	  }
+	}
+	for(int j=j0; j<j1; ++j){
+	  _v[j]._odata[ss] = B[j];
+	}
+      }
+    }
+
+  }
+
+  size_t size() const {
+    return _Nm;
+  }
+
+  void resize(int n) {
+    if (n > _Nm)
+      _v.reserve(n);
+    
+    _v.resize(n,_v[0]._grid);
+
+    if (n < _Nm)
+      _v.shrink_to_fit();
+
+    report(n - _Nm,_v[0]._grid);
+
+    _Nm = n;
+  }
+
+  std::vector<int> getIndex(std::vector<RealD>& sort_vals) {
+
+    std::vector<int> idx(sort_vals.size());
+    iota(idx.begin(), idx.end(), 0);
+
+    // sort indexes based on comparing values in v
+    sort(idx.begin(), idx.end(),
+	 [&sort_vals](int i1, int i2) {return ::fabs(sort_vals[i1]) < ::fabs(sort_vals[i2]);});
+
+    return idx;
+  }
+
+  void reorderInPlace(std::vector<RealD>& sort_vals, std::vector<int>& idx) {
+    GridStopWatch gsw;
+    gsw.Start();
+
+    int nswaps = 0;
+    for (size_t i=0;i<idx.size();i++) {
+      if (idx[i] != i) {
+
+	// find proper place (this could be done in logarithmic time, don't bother for now)
+	size_t j;
+	for (j=i;j<idx.size();j++)
+	  if (idx[j]==i)
+	    break;
+	assert(j!=idx.size());
+	
+	Field _t(_v[0]._grid);
+	_t = _v[idx[j]];
+	_v[idx[j]] = _v[idx[i]];
+	_v[idx[i]] = _t;
+
+	RealD _td = sort_vals[idx[j]];
+	sort_vals[idx[j]] = sort_vals[idx[i]];
+	sort_vals[idx[i]] = _td;
+
+	int _tt = idx[i];
+	idx[i] = idx[j];
+	idx[j] = _tt;
+	
+	nswaps++;
+      }
+    }
+
+    // sort values
+    gsw.Stop();
+    std::cout << GridLogMessage << "Sorted eigenspace in place in " << gsw.Elapsed() << " using " << nswaps << " swaps" << std::endl;
+  }
+
+  void sortInPlace(std::vector<RealD>& sort_vals, bool reverse) {
+
+    std::vector<int> idx = getIndex(sort_vals);
+    if (reverse)
+      std::reverse(idx.begin(), idx.end());
+
+    reorderInPlace(sort_vals,idx);
+
+  }
+
+  void deflate(const std::vector<RealD>& eval,const Field& src_orig,Field& result) {
+    result = zero;
+    int N = (int)_v.size();
+    for (int i=0;i<N;i++) {
+      Field& tmp = _v[i];
+      axpy(result,TensorRemove(innerProduct(tmp,src_orig)) / eval[i],tmp,result);
+    }
+  }
+
+ }; 
+}