Description of envelope

envelope<int MemLoc=internal>		Programmers Guide
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Category:containers,selectors

Component type:type

Description

The storage scheme is for sparse symmetric matrices, where most of the non-zero elements fall near the main diagonal. The storage format is useful in certain factorizations since the fill-ins fall in areas already allocated. This scheme is different than most sparse matrices since the row containers are actually dense, similar to a banded matrix.

 [  1              ]
 [  2  3           ]
 [  4     5        ]
 [        6  7     ]
 [     8     9  10 ]

 
          [ 0  2  5  7 11 ]    Diagonals pointer array
    _______/__/   |  |__\___________
   V     V        V     V           V
 [ 1  2  3  4  0  5  6  7  8  0  9 10 ] Element values array

Example

Definition

matrix.h

Template Parameters

Parameter	Description	Default
`MemLoc`	Specify whether the memory used is "owned" by the matrix or if it was provided to the matrix from some external source (with a pointer to some data)	`internal`

Model of

Members

Member	Where defined	Description
`size_type`
`enum { id = ENVELOPE, oned_id, ext=MemLoc, issparse = 0, index }`

New members

Notes

See also