doc/html/test_permute.html

 // ========================================================================= //
 // This file is part of MyraMath, copyright (c) 2014-2019 by Ryan A Chilton  //
 // and distributed by MyraCore, LLC. See LICENSE.txt for license terms.      //
 // ========================================================================= //

 // For making random permutations p/q
 #include <algorithm>

 // Containers.
 #include <myramath/dense/Vector.h>
 #include <myramath/dense/VectorRange.h>
 #include <myramath/sparse/SparseMatrix.h>
 #include <myramath/sparse/SparseMatrixRange.h>

 // Algorithms.
 #include <myramath/utility/ilinspace.h>
 #include <myramath/dense/swaps.h>
 #include <myramath/dense/frobenius.h>
 #include <myramath/sparse/gemv.h>
 #include <myramath/sparse/permute.h>
 #include <myramath/sparse/Permutation.h>
 #include <myramath/sparse/transpose.h>

 // Reporting.
 #include <tests/myratest.h>

 using namespace myra;

 namespace {

 void test(int I, int J, int N)
   {
   // Make random A and x.
   auto A = SparseMatrix<double>::random(I,J,N);
   auto x = Vector<double>::random(J);
   // Make random permutation P
   auto p = Permutation::random(I);
   auto P = p.make_SparseMatrix<double>();
   // Make random permutation Q
   auto q = Permutation::random(J);
   auto Q = q.make_SparseMatrix<double>();
   // Permute A into P'*A*Q
   auto PAQ = permute(p,A,q);
   // Verify P'*A*Q*b = PAQ*b
   auto b1 = transpose(P)*(A*(Q*x));
   auto b2 = PAQ*x;
   double error = frobenius(b1-b2);
   myra::out() << "|P'*(A*(Q*x)) - (P'*A*Q)*x| = " << error << std::endl;
   }

 } // namespace

 ADD_TEST("permute","[sparse]")
   {
   test(0,0,0);
   test(1,5,3);
   test(7,1,2);
   test(5,5,15);
   test(111,142,4273);
   }
transpose.h
Returns a transposed copy of a SparseMatrix.

VectorRange.h
Interface class for representing subranges of dense Vector&#39;s.

frobenius.h
Routines for computing Frobenius norms of various algebraic containers.

myra::SparseMatrix::random
static SparseMatrix< Number > random(int I, int J, int N)
Generates a random SparseMatrix with size IxJ and (approximately) N nonzeros.
Definition: SparseMatrix.cpp:493

SparseMatrix.h
General purpose compressed-sparse-column (CSC) container.

myra::Vector::random
static Vector< Number > random(int N)
Generates a random Vector of specified size.
Definition: Vector.cpp:276

myra
Definition: syntax.dox:1

swaps.h
Routines related to swap sequences, often used during pivoting.

gemv.h
Signatures for sparse matrix * dense vector multiplies. All delegate to gemm() under the hood...

ilinspace.h
Returns a vector of int&#39;s, over [min,max)

Vector.h
Container for either a column vector or row vector (depends upon the usage context) ...

permute.h
Given a SparseMatrix A and permutations P and Q, returns P&#39;*A*Q.

Permutation.h
Aggregates a (perm, iperm, swaps) triple into a vocabulary type.

myra::Permutation::random
static Permutation random(int N)
Generates a random Matrix of specified size.
Definition: Permutation.cpp:188

SparseMatrixRange.h
Range/Iterator types associated with SparseMatrix.