gtsam
3rdparty
metis
GKlib
GKlib/util.c
Go to the documentation of this file.
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#include <
GKlib.h
>
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/*************************************************************************
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* This file randomly permutes the contents of an array.
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* flag == 0, don't initialize perm
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* flag == 1, set p[i] = i
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**************************************************************************/
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void
gk_RandomPermute
(
size_t
n
,
int
*
p
,
int
flag)
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{
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gk_idx_t
i
, u,
v
;
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int
tmp;
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if
(flag == 1) {
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for
(
i
=0;
i
<
n
;
i
++)
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p
[
i
] =
i
;
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}
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for
(
i
=0;
i
<
n
/2;
i
++) {
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v
=
RandomInRange
(
n
);
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u =
RandomInRange
(
n
);
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gk_SWAP
(
p
[
v
],
p
[u], tmp);
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}
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}
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/************************************************************************/
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/************************************************************************/
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void
gk_array2csr
(
size_t
n
,
size_t
range
,
int
*
array
,
int
*ptr,
int
*
ind
)
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{
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gk_idx_t
i
;
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gk_iset(
range
+1, 0, ptr);
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for
(
i
=0;
i
<
n
;
i
++)
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ptr[
array
[
i
]]++;
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/* Compute the ptr, ind structure */
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MAKECSR
(
i
,
range
, ptr);
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for
(
i
=0;
i
<
n
;
i
++)
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ind
[ptr[
array
[
i
]]++] =
i
;
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SHIFTCSR
(
i
,
range
, ptr);
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}
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/*************************************************************************
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* This function returns the log2(x)
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**************************************************************************/
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int
gk_log2
(
int
a
)
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{
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gk_idx_t
i
;
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for
(
i
=1;
a
> 1;
i
++,
a
=
a
>>1);
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return
i
-1;
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}
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/*************************************************************************
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* This function checks if the argument is a power of 2
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**************************************************************************/
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int
gk_ispow2
(
int
a
)
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{
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return
(
a
== (1<<
gk_log2
(
a
)));
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}
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/*************************************************************************
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* This function returns the log2(x)
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**************************************************************************/
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float
gk_flog2
(
float
a
)
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{
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return
log
(
a
)/
log
(2.0);
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}
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ind
std::vector< int > ind
Definition:
Slicing_stdvector_cxx11.cpp:1
Eigen
Namespace containing all symbols from the Eigen library.
Definition:
jet.h:637
log
const EIGEN_DEVICE_FUNC LogReturnType log() const
Definition:
ArrayCwiseUnaryOps.h:128
gk_idx_t
ssize_t gk_idx_t
Definition:
gk_types.h:22
gk_flog2
float gk_flog2(float a)
Definition:
GKlib/util.c:104
gtsam::range
Double_ range(const Point2_ &p, const Point2_ &q)
Definition:
slam/expressions.h:30
n
int n
Definition:
BiCGSTAB_simple.cpp:1
gk_log2
int gk_log2(int a)
Definition:
GKlib/util.c:83
a
ArrayXXi a
Definition:
Array_initializer_list_23_cxx11.cpp:1
SHIFTCSR
#define SHIFTCSR(i, n, a)
Definition:
gk_macros.h:80
array
Definition:
numpy.h:821
GKlib.h
gk_SWAP
#define gk_SWAP(a, b, tmp)
Definition:
gk_macros.h:19
p
float * p
Definition:
Tutorial_Map_using.cpp:9
RandomInRange
#define RandomInRange(u)
Definition:
gk_macros.h:24
v
Array< int, Dynamic, 1 > v
Definition:
Array_initializer_list_vector_cxx11.cpp:1
gk_ispow2
int gk_ispow2(int a)
Definition:
GKlib/util.c:95
MAKECSR
#define MAKECSR(i, n, a)
Definition:
gk_macros.h:73
gk_RandomPermute
void gk_RandomPermute(size_t n, int *p, int flag)
Definition:
GKlib/util.c:20
i
int i
Definition:
BiCGSTAB_step_by_step.cpp:9
gk_array2csr
void gk_array2csr(size_t n, size_t range, int *array, int *ptr, int *ind)
Converts an element-based set membership into a CSR-format set-based membership.
Definition:
GKlib/util.c:62
gtsam
Author(s):
autogenerated on Fri Nov 1 2024 03:43:07