HP 15c - Manual (Page 142)

142 Section 12: Calculating with Matrices
Example: Dimension matrix A to be a 2×3 matrix.
Keystrokes Display
2
v 2.0000
Keys number of rows into
Y-register.
3
3
Keys number of columns into X-
register.
´mA 3.0000
Dimensions matrix A to be 2×3.
Displaying Matrix Dimensions
There are two ways you can display the dimensions of a matrix:

Press l > followed by the letter key specifying the
matrix. The calculator displays the name of the matrix at the left,
and the number of rows followed by the number of columns at the
right.

Press l m followed by the letter key specifying the
matrix. The calculator places the number of rows in the Y-register
and the number of columns in the X-register.
Keystrokes Display
l > B b 0 0 Matrix B has 0 rows and 0
columns, since it has not been
dimensioned otherwise.
l m A 3.0000
Number of columns in A.
® 2.0000
Number of rows in A.
Changing Matrix Dimensions
Values of matrix elements are stored in memory in order from left to right
along each row, from the first row to the last. If you redimension a matrix to
a smaller size, the required values are reassigned according to the new
dimensions and the extra values are lost. For example, if the 2×3 matrix
shown at the left below is redimensioned to 2×2, then