142 Section 12: Calculating with Matrices

Example: Dimension matrix A to be a 2×3 matrix.

Keystrokes

Display

2 v

2.0000

3

3

´mA

3.0000

Keys number of rows into Y-register.

Keys number of columns into X- register.

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 lmfollowed 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 l>B

lmA

®

Display

 

 

b

0

0 Matrix B has 0 rows and 0

 

 

columns, since it has not been

 

 

dimensioned otherwise.

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