HP 38g Graphing Calculator - Manual (Page 143)

Examples
Filling You can create and fill a matrix with zeros for the diagonal
Matrices elements and ones for the off-diagonal elements using the
MAKEMAT (make matrix) function. For example, entering
MAKEMAT ( IA J, 4,4 ) creates a 4 X 4 matrix with ones for all
elements except zeros on the diagonal. The logical operator
A returns 0 when I (the row number) and J (the column
number) are equal, and returns 1 when they are not equal.
Identity Matrix You can create an identity matrix with the IDENMAT
function. For example, ideimat (2) creates the 2 x2 identity
matrix [[1,0],[0,1]].
Redimension a Suppose the variable MO is a 2x2 matrix containing
Matrix [[3,4],[5,6]]. The programming command
REDIM MO; { 2 , 1 } would redimension it to a matrix of
2rowsxl column, [ [3], [4]]. The command REDiM MO; {4}
would redimension it to the column vector [3,4,5,6]. To see
the redimensioned matrix, either recall the matrix to the edit
line (|A...z|M 0 I ENTER I), or use the Matrix editor
(■ [MATRIX]).
Transposing a The TRN function swaps the row-column and column-row
Matrix elements of a matrix. For instance, element 1,2 (row 1,
column 2) is swapped with element 2,1, element 2,3 is
swapped with element 3,2, and so on.
For example, TRN ( [ [ 1 , 2 ] , [ 3 , 4 ] ] ) creates the matrix
[ [ 1 , 3 ] , [ 2 , 4 ] ] .
Using Matrices 6-13