From 7a349a948532446fe0a8a61afd783c58ba4269c2 Mon Sep 17 00:00:00 2001
From: Wenqing Wang <wenqing.wang@ufz.de>
Date: Fri, 14 Oct 2016 15:19:53 +0200
Subject: [PATCH] [Base] Re-implemented reorderVector and its unit test
---
BaseLib/reorderVector.h | 16 ++++++----------
Tests/BaseLib/TestreorderVector.cpp | 21 +++++++++++++++------
2 files changed, 21 insertions(+), 16 deletions(-)
diff --git a/BaseLib/reorderVector.h b/BaseLib/reorderVector.h
index 9b541a5575f..7ec30155fb4 100644
--- a/BaseLib/reorderVector.h
+++ b/BaseLib/reorderVector.h
@@ -17,23 +17,19 @@
namespace BaseLib
{
/**
- * Reorder a vector by a given index vector.
- * From
- * <a href="reorderV">http://stackoverflow.com/questions/838384/reorder-vector-using-a-vector-of-indices</a>
+ * Reorder a vector by a given index vector.
*
- * Note: The simple version on that page is taken, which is good enough in performance
- * for medium size vectors.
+ * Note: It is good enough in performance for medium size vectors.
*/
template <typename ValueType, typename IndexType>
void reorderVector(std::vector<ValueType>& v,
std::vector<IndexType> const& order)
{
- for (std::size_t s = 1, d; s < order.size(); ++s)
+ std::vector<ValueType> temp_v = v;
+
+ for (std::size_t i=0; i<order.size(); i++)
{
- for (d = order[s]; d < s; d = order[d]);
- if (d == s)
- while (d = order[d], d != s)
- std::swap(v[s], v[d]);
+ v[i] = temp_v[order[i]];
}
}
diff --git a/Tests/BaseLib/TestreorderVector.cpp b/Tests/BaseLib/TestreorderVector.cpp
index 4bc4f104695..3ed1029b4cc 100644
--- a/Tests/BaseLib/TestreorderVector.cpp
+++ b/Tests/BaseLib/TestreorderVector.cpp
@@ -12,6 +12,8 @@
*/
#include <vector>
+#include <algorithm>
+#include <numeric>
#include <gtest/gtest.h>
@@ -19,12 +21,19 @@
TEST(BaseLib_reorderVector, testreorderVector)
{
- std::vector<double> vec {2016.0, 1996.0, 2006.0, 1986.0};
- std::vector<int> order {3, 1, 2, 0};
+ const std::size_t size = 100;
+ std::vector<double> vec(size);
+ std::generate(vec.begin(), vec.end(), std::rand);
+ std::vector<double> vec0 = vec;
+
+ std::vector<int> order(size);
+ std::iota(order.begin(), order.end(), 0);
+ std::random_shuffle(order.begin(), order.end());
+
BaseLib::reorderVector(vec, order);
- EXPECT_EQ(1986.0, vec[0]);
- EXPECT_EQ(1996.0, vec[1]);
- EXPECT_EQ(2006.0, vec[2]);
- EXPECT_EQ(2016.0, vec[3]);
+ for (std::size_t i= 0; i<size; i++)
+ {
+ EXPECT_EQ(vec0[order[i]], vec[i]);
+ }
}
--
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