Programming with LPL
Overview of LPL
22-4
Using the LI-6400
22
:FCT
Main
{
The function
Main
does the following: A prompt to enter 2 numbers is printed
on the display.
"Enter 2 values to average"
The user's response is then parsed into two floating point values, which are
stored in variables
x
and
y
.
&y &x "%f %f"
ENTER
x
and
y
are then summed, and the sum is divided by 2.
x y
+
2
/
This result is printed, and the program pauses until the user presses a key, at
which time the program terminates.
y x "\nThe average of %f and %f is %f\n"
"\n\nPress Any Key"
GETKEY
DROP
The View From the Stack
LPL is a
post-fix
language, whose operation centers about an abstraction
known as a stack. The stack is a ÒLast In - First OutÓ list of objects. The key
to understanding an LPL program is to consider each item (keyword, string,
number, etc.) in the program, and keep track of what it does to the stack. WeÕll
go through the program in Figure 22-1 again, this time with special emphasis
on the stack.
We illustrate stack operations by picturing the stack as a horizontal collection
of boxes, with the top of the stack being the right-most box. We start with an
empty stack. First, the prompting stringÕs address is pushed onto the stack,
and the
pops it back off.
Operation
The Stack
3
2
1
1. Stack is empty:
2. "Enter 2 ..."
Address of "Enter 2..."
3.
Summary of Contents for LI-6400
Page 1: ...Using the LI 6400 Portable Photosynthesis System ...
Page 15: ...Part I The Basics ...
Page 16: ......
Page 174: ...Making Measurements Answers to Questions 4 56 Using the LI 6400 4 ...
Page 175: ...Part II Useful Details ...
Page 176: ......
Page 200: ...Standard Tools Power ON Hooks 5 24 Using the LI 6400 5 ...
Page 214: ...Real Time Data Real Time Graphics 6 14 Using the LI 6400 6 ...
Page 234: ...Environmental Control Light Control 7 20 Using the LI 6400 7 ...
Page 244: ...Light Sensor Considerations Gallium Arsenide Phosphide GaAsP Sensor 8 10 Using the LI 6400 8 ...
Page 288: ...Data Logging Making Your Own AutoPrograms 9 44 Using the LI 6400 9 ...
Page 289: ...Part III Working With Files ...
Page 290: ......
Page 312: ...The LPL File System Troubleshooting 10 22 Using the LI 6400 10 ...
Page 340: ...Downloading Files Using a Data Capture Program 11 28 Using the LI 6400 11 ...
Page 375: ...Part IV Configuration Issues ...
Page 376: ......
Page 420: ...Defining User Variables Old Style vs New Style 15 18 Using the LI 6400 15 ...
Page 454: ...Using an Energy Balance Further Reading 17 12 Using the LI 6400 17 ...
Page 455: ...Part V Maintenance Troubleshooting ...
Page 456: ......
Page 572: ...Troubleshooting Useful Information 20 46 Using the LI 6400 20 ...
Page 593: ...Part VI Programming ...
Page 594: ......
Page 622: ...Programming with LPL Compiler Directives 22 28 Using the LI 6400 22 ...
Page 846: ...Index I 16 Using the LI 6400 ...