From e6d563ee97f19b1e901c02b4ccceca0e270e75b4 Mon Sep 17 00:00:00 2001
From: Thomas Fischer <thomas.fischer@ufz.de>
Date: Fri, 11 Nov 2011 11:30:43 +0100
Subject: [PATCH] added method getValue() to template class CRSMatrix
---
MathLib/LinAlg/Sparse/CRSMatrix.h | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/MathLib/LinAlg/Sparse/CRSMatrix.h b/MathLib/LinAlg/Sparse/CRSMatrix.h
index 04965cd46d3..65e503ddc2f 100644
--- a/MathLib/LinAlg/Sparse/CRSMatrix.h
+++ b/MathLib/LinAlg/Sparse/CRSMatrix.h
@@ -125,6 +125,22 @@ public:
return 1;
}
+ double getValue(IDX_TYPE row, IDX_TYPE col)
+ {
+ assert(0 <= row && row < MatrixBase::_n_rows);
+
+ // linear search - for matrices with many entries per row binary search is much faster
+ const IDX_TYPE idx_end (_row_ptr[row+1]);
+ IDX_TYPE j(_row_ptr[row]), k;
+
+ while (j<idx_end && (k=_col_idx[j]) <= col) {
+ if (k == col) {
+ return _data[j];
+ }
+ j++;
+ }
+ return 0.0;
+ }
/**
* This is the constant access operator to a non-zero matrix entry.
--
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