Important: The linalg package has been deprecated. Use the superseding packages, LinearAlgebra and VectorCalculus, instead.

- For information on migrating linalg code to the new packages, see examples/LinearAlgebraMigration.

The procedure call indexfunc(A) returns the indexing function for the array A.

This could be one of the standard indexing functions such as identity, symmetric, or diagonal, or the name of a user-defined indexing function.

If there is no indexing function specified for the array A, then indexfunc will return NULL.

The command with(linalg,indexfunc) allows the use of the abbreviated form of this command.

$\mathrm{with}\left(\mathrm{linalg}\right)\:$

$A≔\mathrm{array}\left(1..2\,1..2\,\left[\left[1\,0\right]\,\left[0\,1\right]\right]\right)$

$A≔\left[\begin{array}{cc}1& 0\\ 0& 1\end{array}\right]$

$\mathrm{indexfunc}\left(A\right)$

$B≔\mathrm{array}\left(1..2\,1..2\,\left[\left[1\,0\right]\,\left[0\,1\right]\right]\,'\mathrm{symmetric}'\right)$

$B≔\left[\begin{array}{cc}1& 0\\ 0& 1\end{array}\right]$

$\mathrm{indexfunc}\left(B\right)$

$\mathrm{symmetric}$