 
 
 
14.4.2  Defining sparse matrices
A matrix is sparse if most of its elements are 0. To specify a
sparse matrix, it is easier to define the non-zero elements.
This can be done with a table (see Section 14.4.1).
The matrix command (see Section 14.2.4) or the
convert command (see Section 10.1.10) can then
turn the table into a matrix.
Example
First, define the non-zero elements.
| A:=table((0,0)=1,(1,1)=2,(2,2)=3,(3,3)=4,(4,4)=5) | 
or:
| purge(A);
 A[0..4,0..4]:=[1,2,3,4,5] | 
This table can be converted to a matrix with either the
convert command or the matrix command.
or:
|  | | |  | | ⎡ ⎢
 ⎢
 ⎢
 ⎢
 ⎢
 ⎣
 | | 1 | 0 | 0 | 0 | 0 |  | 0 | 2 | 0 | 0 | 0 |  | 0 | 0 | 3 | 0 | 0 |  | 0 | 0 | 0 | 4 | 0 |  | 0 | 0 | 0 | 0 | 5 | 
 | ⎤ ⎥
 ⎥
 ⎥
 ⎥
 ⎥
 ⎦
 | 
 | 
 |  |  |  |  |  |  |  |  |  |  | 
 | 
 
 
