alibIndexNdTo1d
For an
n-dimensional array, convert a set of
n-dimensional indices into a set of one-dimensional indices, i.e., convert a set of multidimensional indices into their flat equivalents. The PV-WAVE API for this routine is the
INDEX_CONV Function.
Prototype
void alibIndexNdTo1d( wvlong n, wvlong *d, wvlong m, wvlong p, wvlong **i,wvlong *j )
Parameters
n — (Input) The number of dimensions for the reference array. This array, possibly virtual, is the array to which the indices refer.
*d — (Input) The n-element array of dimensions for the reference array.
m — (Input) The number of indices to be converted.
p — (Input) The number of coordinates supplied in the set of n-dimensional indices. Normally p = n, but setting p < n lets only the first p coordinates be specified, with the remaining coordinates implicitly assuming the value 0.
**i — (Input) The p-element array of pointers to m-element arrays defining the set of m n-dimensional indices into the reference array.
*j — (Input/Output) The m-element array. On return, j contains the one-dimensional equivalents to n-dimensional indices i. For a reference array c, the relationship between the sets of indices is:
c[ j[k] ] = c[ i[0][k], ..., i[p-1][k], 0, ..., 0 ]
where if p = n then:
c[ j[k] ] = c[ i[0][k], ..., i[n-1][k] ]
Example
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "alib.h"
void main() { /* array of dimensions to use for two-dimensional,
three-dimensional, and four-dimensional examples */
wvlong dims[4] = {2,2,3,4}; /* allocate index arrays big enough for two-dimensional,
three-dimensional, and four-dimensional examples */
wvlong k, *h, *j, *i[4];
h = (wvlong*)malloc(48*sizeof(wvlong));
j = (wvlong*)malloc(48*sizeof(wvlong));
for (k=0; k<4; k++) i[k] = (wvlong*)malloc(48*sizeof(wvlong));
/* make enough n-dimensional indices to use for the
two-dimensional, three-dimensional, and four-dimensional
examples */
alibinit( NULL, NULL, NULL, NULL );
alibIndexl( 48, 0, 1, h );
alibIndex1dToNd( 4, dims, 48, h, i );
printf( "\n\n for a (3,4) array, convert its set of two-dimensional indices \n" );
printf( " to one-dimensional indices, print both sets of indices side-by-side \n" );
alibIndexNdTo1d( 2, &dims[2], 12, 2, &i[2], j );
for ( k=0; k<12; k++ ) { printf( "%4lld %4lld %16lld\n",
i[2][k], i[3][k], j[k] );
}
printf( "\n\n for a (2,3,4) array, convert its set of three-dimensional indices \n" );
printf( " to one-dimensional indices, print both sets of indices side-by-side \n" );
alibIndexNdTo1d( 3, &dims[1], 24, 3, &i[1], j );
for ( k=0; k<24; k++ ) { printf( "%4lld %4lld %4lld %16lld\n",
i[1][k], i[2][k], i[3][k], j[k] );
}
printf( "\n\n for a (2,2,3,4) array, convert its set of four-dimensional indices \n" );
printf( " to one-dimensional indices, print both sets of indices side-by-side \n" );
alibIndexNdTo1d( 4, dims, 48, 4, i, j );
for ( k=0; k<48; k++ ) { printf( "%4lld %4lld %4lld %4lld %16lld\n",
i[0][k], i[1][k], i[2][k], i[3][k], j[k] );
}
}
Output:
for a (3,4) array, convert its set of two-dimensional indices
to one-dimensional indices, print both sets of indices side-by-side
0 0 0
0 1 1
0 2 2
0 3 3
1 0 4
1 1 5
1 2 6
1 3 7
2 0 8
2 1 9
2 2 10
2 3 11
for a (2,3,4) array, convert its set of three-dimensional indices
to one-dimensional indices, print both sets of indices side-by-side
0 0 0 0
0 0 1 1
0 0 2 2
0 0 3 3
0 1 0 4
0 1 1 5
0 1 2 6
0 1 3 7
0 2 0 8
0 2 1 9
0 2 2 10
0 2 3 11
1 0 0 12
1 0 1 13
1 0 2 14
1 0 3 15
1 1 0 16
1 1 1 17
1 1 2 18
1 1 3 19
1 2 0 20
1 2 1 21
1 2 2 22
1 2 3 23
for a (2,2,3,4) array, convert its set of four-dimensional indices
to one-dimensional indices, print both sets of indices side-by-side
0 0 0 0 0
0 0 0 1 1
0 0 0 2 2
0 0 0 3 3
0 0 1 0 4
0 0 1 1 5
0 0 1 2 6
0 0 1 3 7
0 0 2 0 8
0 0 2 1 9
0 0 2 2 10
0 0 2 3 11
0 1 0 0 12
0 1 0 1 13
0 1 0 2 14
0 1 0 3 15
0 1 1 0 16
0 1 1 1 17
0 1 1 2 18
0 1 1 3 19
0 1 2 0 20
0 1 2 1 21
0 1 2 2 22
0 1 2 3 23
1 0 0 0 24
1 0 0 1 25
1 0 0 2 26
1 0 0 3 27
1 0 1 0 28
1 0 1 1 29
1 0 1 2 30
1 0 1 3 31
1 0 2 0 32
1 0 2 1 33
1 0 2 2 34
1 0 2 3 35
1 1 0 0 36
1 1 0 1 37
1 1 0 2 38
1 1 0 3 39
1 1 1 0 40
1 1 1 1 41
1 1 1 2 42
1 1 1 3 43
1 1 2 0 44
1 1 2 1 45
1 1 2 2 46
1 1 2 3 47
Version 2017.0
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