Exchanging The X- And Y-Registers In The Stack - HP -32S Owner's Manual

Suppose the stack is filled with 1, 2, 3, 4 (press 11enter 121 enter 13
Ienter I 4). Pressing |R*I four times rolls the numbers all the way
around and back to where they started:
T
1
LH]
4
EE
3
LrD
2
LIE
1
Z
2
1 4 3
2
Y
3
2 1 4
3
X
4
3 2 1 4
What was in the X-register rotates around and enters the T-register.
Notice that the contents of the registers are rolled. The registers them
selves maintain their positions, and the X-register is always displayed.
Exchanging the X- and Y-Registers in the Stack
Another key that manipulates the stack contents is |x$y|(x exchange y).
It swaps the contents of the X- and Y-registers without affecting the
rest of the stack. Pressing|x*y| twice, of course, restores the original
order of the contents.
The |x$y[ function is used primarily for two purposes:
• To view y and then return it to the Y-regjster (press fxiyl twice).
Some functions yield two results: one into the X-register and one
into the Y-regjster. An example is {y,x*6,r }, which converts rect
angular coordinates in the X- and Y-registers into polar coordinates
in the X- and Y-registers.
• To swap the order of numbers in a calculation. For example, an
easy way to calculate 9 •*• (13 x 8) is to press 13 Ienter I 8 09
a s .
2: The Automatic Memory Stack 37