Random Numbers And Other Functions Random Numbers And Other Functions - Commodore SX-65 Portable User Manual

RANDOM NUMBERS AND OTHER FUNCTIONS
The 64 also has built-in functions that you can use to perform special tasks.
Functions are like built-in programs included in BASIC. The great advantage of
these built-in functions is that you don't have to type in a number of statements
every time you want to perform a specialized calculation. Instead, all you do is
type the command for ihe function you want and the computer does all the rest.
These built-in functions include figuring square roots (SQR), finding out the
contents of a memory location (PEEK), generating random numbers (RND), etc.
Appendix C lists all the functions available on your computer.
One function you can have a lot of fun with is the random number function,
RND. If you want to design a game or an educational program, you'll often need
to be able to program your computer to make up random numbers. For exam
ple, you'd need to do this to simulate the tossing of dice. Of course you could
write a program that wouid generate these random numbers, but it's much
easier to be able to do this just by calling upon the prewritten RaNDom number
function.
To see how RND works, try this short program:
NEW
10 FOR X = 1 TO 10
20 PRINT RND(1),
30 NEXT
IF YOU LEAVE OUT THE COMMA, YOUR
LIST OF NUMBERS APPEARS AS 1 COLUMN
When you RUN this program, the screen displays:
.789280697
.256373663
.682952381
.402342724
.158209063
.664673958
.0123442287
3.90587279E-04
.879300926
.245596701
Your numbers don't match? It would be incredible if they did because the
program generates a completely random list of ten numbers.
If you RUN the program a few more time, you'll see that the results are
always different. Though the numbers don't have a pattern, you'll notice a few
consistencies about the list the program displays.
For one thing, the results are always between 1 and 0. but never equal to 1 or
0. For another, the numbers are real numbers (with decimal points).
Now, we started out to simulate dice tosses, and the results from this pro
gram aren't exactly what we're looking for. Now we'll add a few more features
to this program to get what we want.
First, add this line to the program to replace line 20, and RUN the program
aaain:
20 PRINT 6*RND(1),
RUN
3.60563664
5.48602315
3.10045018
3.91302584
2.32056144
4.52687513
1.09650123
4.39052168
5.06321506
4.10781302
53
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RANDOM NUMBERS AND OTHER FUNCTIONS
The 64 also has buill·in functions that you can use to perform special tasks.
Functions are like built·in programs included in BASIC. The great advantage of
these built·in functions is that you don't have to type in a number of statements
every time you want to perform a specialized calculation. Instead, all you do is
type the command for Ihe funct ion you want and the computer does all the rest.
These built·in funct ions include figuring square roots (SOR), finding out the
contents of a memory location (PEEK), generating random numbers (RND), etc.
Appendix C lists all the functions available on you r computer.
One function you can have a lot of fun with is the rand om number function ,
RND.
If
you want to design a game or an educational program, yo u'll often need
to be able to program your computer to make up random numbers. For exam·
pie, yo u'd need to do this to simulate the tossing of dice. Of course you could
write a program that wou ld generate these random numbers, bu t it's much
easier to be able to do this just by cal ling upon the prewritten RaNDom number
function.
To see how RND works, try this short program:
NEW
10 FOR X
=
1 TO 10
20 PRINT RND (1),
30 NEXT
IF YOU LEAVE OUT THE COMMA. YOUR
LIST OF NUMBERS APPEARS AS 1 COLUMN
When you RUN this program, the screen displays:
.789280697
.256373663
.682952381
.402342724
.158209063
.664673958
.0123442287
3.90587279E - 04
.879300926
.245596701
Your numbers don't match? It woul d be incredible if they did because the
program generates a completely random list of ten numbers.
If you RUN the program a few more time, you'll see that the results are
always different. Th ough the numbers don 't have a pattern, you' ll notice a few
cons istencies about the list the program displays.
For one thing , the results are always between 1 and 0, but never equal to 1 or
O. For another, the numbers are real numbers (with decimal pOints).
Now, we started out to simulate dice tosses, and the results from this pro.
gram aren't exactly what we're looking for. Now we'll add a few more features
to this program to get what we want.
First, add this line to the program to replace line 20, and RUN the program
again:
20 PRINT 6'RND(1),
RUN
3.60563664
5.48602315
3. 10045018
3.91302584
2.32056144
4.52687513
1.09650123
4.39052168
5.0632 1506
4.1078 1302
53