Storing the elements of a complex matrix – HP 15c User Manual

Page 162

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162 Section 12: Calculating with Matrices

Suppose you need to do a calculation with a complex matrix that is not
written as the sum of a real matrix and an imaginary matrix – as was the
matrix Z in the example above – but rather written with an entire complex
number in each element, such as

22

22

21

21

12

12

11

11

iy

x

iy

x

iy

x

iy

x

Z

.

This matrix can be represented in the calculator by a real matrix that looks
very similar – one that is derived simply by ignoring the i and the + sign.
The 2 × 2 matrix Z shown above, for example, can be represented in the
calculator in ―complex‖ form by the 2 × 4 matrix.

22

22

21

21

12

12

11

11

y

x

y

x

y

x

y

x

C

Z

A

.

The superscript C signifies that the complex matrix is represented in a
"complex-like" form.

Although a complex matrix can be initially represented in the calculator by
a matrix of the form shown for Z

C

, the transformations used for multiplying

and inverting a complex matrix presume that the matrix is represented by a
matrix of the form shown for Z

P

. The HP-15C provides two transformations

that convert the representation of a complex matrix between Z

C

and Z

P

:

Pressing

Transforms

Into

´p

Z

C

Z

P

| c

Z

P

Z

C

To do either of these transformations, recall the descriptor of Z

C

or Z

P

into

the display, then press the keys shown above. The transformation is done to
the specified matrix; the result matrix is not affected.

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