Texas Instruments TI-83 PLUS - Manual (Page 280)

TI-83 Plus Matrices 277
Fill( value , matrixname )
identity(
identity( returns the identity matrix of dimension rows × dimension columns.
identity( dimension )
randM(
randM( (create random matrix) returns a rows × columns random matrix of
integers ‚ L 9 and  9. The seed value stored to the rand function controls
the values (Chapter 2).
randM( rows , columns )
augment(
augment( appends matrixA to matrixB as new columns. matrixA and matrixB
both must have the same number of rows.