root / www / HPL_perm.html
Historique | Voir | Annoter | Télécharger (2,08 ko)
| 1 |
<HTML>
|
|---|---|
| 2 |
<HEAD>
|
| 3 |
<TITLE>HPL_perm HPL 2.0 Library Functions September 10, 2008</TITLE> |
| 4 |
</HEAD>
|
| 5 |
|
| 6 |
<BODY BGCOLOR="WHITE" TEXT = "#000000" LINK = "#0000ff" VLINK = "#000099" |
| 7 |
ALINK = "#ffff00"> |
| 8 |
|
| 9 |
<H1>Name</H1> |
| 10 |
<B>HPL_perm</B> Combine 2 index arrays - Generate the permutation. |
| 11 |
|
| 12 |
<H1>Synopsis</H1> |
| 13 |
<CODE>#include "hpl.h"</CODE><BR><BR> |
| 14 |
<CODE>void</CODE> |
| 15 |
<CODE>HPL_perm(</CODE> |
| 16 |
<CODE>const int</CODE> |
| 17 |
<CODE>N</CODE>, |
| 18 |
<CODE>int *</CODE> |
| 19 |
<CODE>LINDXA</CODE>, |
| 20 |
<CODE>int *</CODE> |
| 21 |
<CODE>LINDXAU</CODE>, |
| 22 |
<CODE>int *</CODE> |
| 23 |
<CODE>IWORK</CODE> |
| 24 |
<CODE>);</CODE> |
| 25 |
|
| 26 |
<H1>Description</H1> |
| 27 |
<B>HPL_perm</B> |
| 28 |
combines two index arrays and generate the corresponding |
| 29 |
permutation. First, this function computes the inverse of LINDXA, and |
| 30 |
then combine it with LINDXAU. Second, in order to be able to perform |
| 31 |
the permutation in place, LINDXAU is overwritten by the sequence of |
| 32 |
permutation producing the same result. What we ultimately want to |
| 33 |
achieve is: U[LINDXAU[i]] := U[LINDXA[i]] for i in [0..N). After the |
| 34 |
call to this function, this in place permutation can be performed by |
| 35 |
for i in [0..N) swap U[i] with U[LINDXAU[i]]. |
| 36 |
|
| 37 |
<H1>Arguments</H1> |
| 38 |
<PRE>
|
| 39 |
N (global input) const int |
| 40 |
On entry, N specifies the length of the arrays LINDXA and |
| 41 |
LINDXAU. N should be at least zero. |
| 42 |
</PRE>
|
| 43 |
<PRE>
|
| 44 |
LINDXA (global input/output) int * |
| 45 |
On entry, LINDXA is an array of dimension N containing the |
| 46 |
source indexes. On exit, LINDXA contains the combined index |
| 47 |
array. |
| 48 |
</PRE>
|
| 49 |
<PRE>
|
| 50 |
LINDXAU (global input/output) int * |
| 51 |
On entry, LINDXAU is an array of dimension N containing the |
| 52 |
target indexes. On exit, LINDXAU contains the sequence of |
| 53 |
permutation, that should be applied in increasing order to |
| 54 |
permute the underlying array U in place. |
| 55 |
</PRE>
|
| 56 |
<PRE>
|
| 57 |
IWORK (workspace) int * |
| 58 |
On entry, IWORK is a workarray of dimension N. |
| 59 |
</PRE>
|
| 60 |
|
| 61 |
<H1>See Also</H1> |
| 62 |
<A HREF="HPL_plindx1.html">HPL_plindx1</A>, |
| 63 |
<A HREF="HPL_pdlaswp01N.html">HPL_pdlaswp01N</A>, |
| 64 |
<A HREF="HPL_pdlaswp01T.html">HPL_pdlaswp01T</A>. |
| 65 |
|
| 66 |
</BODY>
|
| 67 |
</HTML>
|