From 4a54f1473eb809ab616a064774a0c831b7450624 Mon Sep 17 00:00:00 2001
From: Jesper Andersson <jesper@fmrib.ox.ac.uk>
Date: Tue, 18 Sep 2007 19:11:58 +0000
Subject: [PATCH] Added SetColumn() to SpMat
---
SpMat.h | 50 +++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 45 insertions(+), 5 deletions(-)
diff --git a/SpMat.h b/SpMat.h
index 32a37a7..2748f3a 100644
--- a/SpMat.h
+++ b/SpMat.h
@@ -101,8 +101,9 @@ public:
T Peek(unsigned int r, unsigned int c) const;
T operator()(unsigned int r, unsigned int c) const {return(Peek(r,c));} // Read-only
- void Set(unsigned int r, unsigned int c, const T& v) {here(r,c) = v;}
- void AddTo(unsigned int r, unsigned int c, const T& v) {here(r,c) += v;}
+ void Set(unsigned int r, unsigned int c, const T& v) {here(r,c) = v;} // Set a single value
+ void SetColumn(unsigned int c, const NEWMAT::ColumnVector& col, double eps=0.0); // Set a whole column (obliterating what was there before)
+ void AddTo(unsigned int r, unsigned int c, const T& v) {here(r,c) += v;} // Add value to a single (possibly existing) value
SpMat<T>& operator+=(const SpMat& M)
{
@@ -243,9 +244,9 @@ private:
//
// The concept of an accumulator was "borrowed" from Gilbert et al.
// 92. It is intended as a helper class for SpMat and is used to
-// hold the content of one column of a matrix C where C is a
-// sparse matrix resulting from C=A*B where A and B are sparse
-// matrices.
+// hold the content of one column of a matrix. This column can then
+// be accessed both by indexing a certain element, and also by indexing
+// only non-zero elements.
//
//@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@ -488,6 +489,45 @@ const SpMat<T> SpMat<T>::t() const
return(t_mat);
}
+/////////////////////////////////////////////////////////////////////
+//
+// Sets the values of an entire column, destroying any previous content.
+//
+/////////////////////////////////////////////////////////////////////
+
+template<class T>
+void SpMat<T>::SetColumn(unsigned int c, // Column #
+ const NEWMAT::ColumnVector& col, // The values in that column
+ double eps) // Any value <= eps is treated as a zero
+{
+ if (c < 1 || c > _n) throw SpMatException("SetColumn: column index out of range");
+ if (static_cast<unsigned int>(col.Nrows()) != _m) throw SpMatException("SetColumn: column size mismatch");
+
+ Accumulator<T> acc(_m);
+ double *colp = col.Store();
+
+ for (unsigned int i=0; i<_m; i++) {
+ if (colp[i] > eps) acc(i) = static_cast<T>(colp[i]);
+ }
+
+ std::vector<unsigned int>& ri = _ri[c-1];
+ std::vector<T>& val = _val[c-1];
+ unsigned int old_sz = ri.size();
+ if (old_sz) {
+ ri = std::vector<unsigned int>(acc.NO());
+ val = std::vector<T>(acc.NO());
+ }
+ else {
+ ri.resize(acc.NO());
+ val.resize(acc.NO());
+ }
+ for (unsigned int i=0; i<acc.NO(); i++) {
+ ri[i] = acc.ri(i);
+ val[i] = acc.val(i);
+ }
+ _nz += (acc.NO() - old_sz);
+}
+
/////////////////////////////////////////////////////////////////////
//
// Returns value at position i,j (one offset)
--
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