Reference Guide

1-8 RPL Programming

For example, if the stack looks like this:

then

→ a

creates local variable a = 20.

→ ab

creates local variables a = 6 and b = 20.

→ abc

creates local variables a = 10, b = 6, and c = 20.

The defining procedure then uses the local variables to do calculations.

Local variable structures have these advantages:



The → command stores the values from the stack in the corresponding variables — you don’t need to explicitly

execute STO.



Local variables automatically disappear when the defining procedure for which they are created has completed

execution. Consequently, local variables don’t appear in the VAR menu, and they occupy user memory only

during program execution.



Local variables exist only within their defining procedure — different local variable structures can use the same

variable names without conflict.

Example:

The following program SPHLV calculates the volume of a spherical cap using local variables. The

defining procedure is an algebraic expression.

Level 2 Level 1

→

Level 1

r h

→

volume

Program: Comments:

→ r h

Creates local variables r and h for the radius

of the sphere and height of the cap.

'1/3*π*h^2*(3*r-h)'

Expresses the defining procedure. In this

program, the defining procedure for the local

variable structure is an algebraic expression.

→NUM

Converts expression to a number.

SPHLV

Stores the program in variable SPHLV.

Now use SPHLV to calculate the volume of a spherical cap of radius r =10 and height h = 3. Enter the data on the

stack in the correct order, then execute the program.

%SPHLV%