HP 15c User Manual

Page 150

Advertising
background image

150 Section 12: Calculating with Matrices

One-Matrix Operations:

Sign Change, Inverse, Transpose, Norms, Determinant

Keystroke(s)

Result in

X-register

Effect on Matrix

Specified in

X-register

Effect on Result

Matrix

No change.

Changes sign of
all elements.

None. ‡


(´∕ in
User Mode)

Descriptor of
result matrix.

None. ‡

Inverse of
specified matrix.
§

´>

4

Descriptor of
transpose.

Replaced by
transpose.

None. ‡

´>

7

Row norm of
specified
matrix.*

None.

None.

´>

8

Frobenius or
Euclidean norm
of specified
matrix.

None.

None.

´>

9

Determinant of
specified
matrix.

None.‡

LU decomposi-

tion of specified
matrix.§

*

The row norm is the largest sum of the absolute values of the elements in
each row of the specified matrix.

The Frobenius of Euclidean norm is the square root of the sum of the
squares of all elements in the specified matrix.

Unless the result matrix is the same matrix specified in the X-register.

§

If the specified matrix is a singular matrix (that is, one that doesn’t have an
inverse), then the HP-15C modifies the LU form by an amount that is
usually small compared to round-off error. For ∕, the calculated inverse
is the inverse of a matrix close to the original, singular matrix. (Refer to the
HP-15C Advanced Functions Handbook for further information.)

Advertising