vsip_dmget_p - Get Matrix Element

Core

This manual is preliminary and incomplete.
While our Core implementation implements all functions given in the standard we are still working on completing this documentation.

Please refer to the VSIPL standard for a complete function reference of the Core profile until we have completed work on this documentation.

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1.4.4 vsip_dmget_p - Get Matrix Element

vsip_scalar_f vsip_mget_f(const vsip_mview_f *v, vsip_index i, vsip_index j); 
vsip_cscalar_f vsip_cmget_f(const vsip_cmview_f *v, vsip_index i, vsip_index j);

Description

This function retrieves the value of a specific element from a matrix view. The element is identified by its row and column indices (0-based).

Parameters

const vsip_dmview_p* v: Pointer to the matrix view.
vsip_index i: Row index of the element to retrieve (0-based).
vsip_index j: Column index of the element to retrieve (0-based).

Return Value

Returns the value of the matrix element at position $(i,j)$ as a vsip_dscalar_p .

Example

vsip_mview_f *matrix; 
vsip_scalar_f value; 
vsip_index i, j; 
 
// Create and initialize a matrix 
matrix = vsip_mcreate_f(5, 5, VSIP_ROW, VSIP_MEM_NONE); 
 
// Fill the matrix with some values 
for (i = 0; i < 5; i++) { 
    for (j = 0; j < 5; j++) { 
        vsip_mput_f(matrix, i, j, i * 5 + j + 1); 
    } 
} 
 
// Retrieve specific elements 
value = vsip_mget_f(matrix, 0, 0);  // Top-left corner 
printf("Element at (0,0): %f\n", value); 
 
value = vsip_mget_f(matrix, 2, 3);  // Middle element 
printf("Element at (2,3): %f\n", value); 
 
value = vsip_mget_f(matrix, 4, 4);  // Bottom-right corner 
printf("Element at (4,4): %f\n", value);

Notes

The function does not perform bounds checking and may return an error or undefined value if the indices are out of range.
For submatrix views, the indices are relative to the submatrix, not the parent matrix.

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