gtsam
3rdparty
Eigen
doc
examples
TutorialInplaceLU.cpp
Go to the documentation of this file.
1
#include <iostream>
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struct
init
{
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init
() { std::cout <<
"["
<<
"init"
<<
"]"
<< std::endl; }
4
};
5
init
init_obj
;
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// [init]
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#include <iostream>
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#include <Eigen/Dense>
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using namespace
std
;
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using namespace
Eigen
;
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int
main
()
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{
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MatrixXd
A
(2,2);
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A
<< 2, -1, 1, 3;
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cout <<
"Here is the input matrix A before decomposition:\n"
<<
A
<< endl;
18
cout <<
"[init]"
<< endl;
19
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cout <<
"[declaration]"
<< endl;
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PartialPivLU<Ref<MatrixXd>
>
lu
(
A
);
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cout <<
"Here is the input matrix A after decomposition:\n"
<<
A
<< endl;
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cout <<
"[declaration]"
<< endl;
24
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cout <<
"[matrixLU]"
<< endl;
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cout <<
"Here is the matrix storing the L and U factors:\n"
<<
lu
.matrixLU() << endl;
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cout <<
"[matrixLU]"
<< endl;
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cout <<
"[solve]"
<< endl;
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MatrixXd
A0
(2,2);
A0
<< 2, -1, 1, 3;
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VectorXd
b
(2);
b
<< 1, 2;
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VectorXd
x
=
lu
.solve(
b
);
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cout <<
"Residual: "
<< (
A0
*
x
-
b
).norm() << endl;
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cout <<
"[solve]"
<< endl;
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cout <<
"[modifyA]"
<< endl;
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A
<< 3, 4, -2, 1;
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x
=
lu
.solve(
b
);
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cout <<
"Residual: "
<< (
A0
*
x
-
b
).norm() << endl;
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cout <<
"[modifyA]"
<< endl;
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cout <<
"[recompute]"
<< endl;
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A0
=
A
;
// save A
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lu
.compute(
A
);
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x
=
lu
.solve(
b
);
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cout <<
"Residual: "
<< (
A0
*
x
-
b
).norm() << endl;
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cout <<
"[recompute]"
<< endl;
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cout <<
"[recompute_bis0]"
<< endl;
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MatrixXd
A1
(2,2);
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A1
<< 5,-2,3,4;
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lu
.compute(
A1
);
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cout <<
"Here is the input matrix A1 after decomposition:\n"
<<
A1
<< endl;
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cout <<
"[recompute_bis0]"
<< endl;
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cout <<
"[recompute_bis1]"
<< endl;
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x
=
lu
.solve(
b
);
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cout <<
"Residual: "
<< (
A1
*
x
-
b
).norm() << endl;
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cout <<
"[recompute_bis1]"
<< endl;
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}
Eigen
Namespace containing all symbols from the Eigen library.
Definition:
jet.h:637
Eigen::PartialPivLU
LU decomposition of a matrix with partial pivoting, and related features.
Definition:
ForwardDeclarations.h:269
b
Scalar * b
Definition:
benchVecAdd.cpp:17
x
set noclip points set clip one set noclip two set bar set border lt lw set xdata set ydata set zdata set x2data set y2data set boxwidth set dummy x
Definition:
gnuplot_common_settings.hh:12
A0
static const double A0[]
Definition:
expn.h:5
A
Matrix< SCALARA, Dynamic, Dynamic, opt_A > A
Definition:
bench_gemm.cpp:48
init::init
init()
Definition:
TutorialInplaceLU.cpp:3
main
int main()
Definition:
TutorialInplaceLU.cpp:13
init_obj
init init_obj
Definition:
TutorialInplaceLU.cpp:5
lu
cout<< "Here is the matrix m:"<< endl<< m<< endl;Eigen::FullPivLU< Matrix5x3 > lu(m)
std
Definition:
BFloat16.h:88
A1
static const double A1[]
Definition:
expn.h:6
init
Definition:
TutorialInplaceLU.cpp:2
gtsam
Author(s):
autogenerated on Fri Nov 1 2024 03:43:01