Random

[Deleted User]

Hi , I was wondering if anybody knew if you could put a limit on "RANDOM"· , say you only want numers from 0 to 13 . Is it possible to make it so RANDOM could only choose between those number's

thanks,
brian

Paul Baker

Using the modulo (//) operator will place the number into a range of 0 through n-1, so if you made a random number r, r//14 will return a number between 0 and 13.

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.

[Deleted User]

so is r the variable name

r var byte

random r//14

also can you use more than one random in a row, like

random color
random character
random ypos
random xpos

Fe2o3Fish

truckwiz said...
so is r the variable name

r var byte

random r//14

Well, look at the syntax for the RANDOM command in the PBASIC Help file.

RANDOM [i]variable[/i]

So.... you really do something more like this

RANDOM r
r = r // 14

The first line gets a random number and the second line reduces that
random number to 0 to 13. You don't necessarily have to reassign it
back to 'r' -- you can use "r // 14" as part of an expression. BUT, if
you need that value again the MODULO operator will have to be calculated again.
{EDIT: Oooppsss! After using the modulo operator on the output of RANDOM
you REALLY don't want to reassign it back to 'r' (in this case) because the value
of 'r' will be used to seed the random number generator next time you call execute
RANDOM r. This will then cause your code to use the same 14 numbers from RANDOM
over and over again. Probably not what you want.}

truckwiz said...
also can you use more than one random in a row, like

random color
random character
random ypos
random xpos

Yup!

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-Rusty-
--
Rusty Haddock = KD4WLZ = rusty@fe2o3.lonestar.org
**Out yonder in the Van Alstyne (TX) Metropolitan Area**
Microsoft is to software what McDonalds is to gourmet cooking

Post Edited (Fe2o3Fish) : 10/22/2006 5:01:59 AM GMT

[Deleted User]

Heres my screen saver program , what am i doing wrong ??

' {$STAMP BS2}
' {$PBASIC 2.5}
'screen saver program
color VAR Byte
xpos VAR Byte
ypos VAR Byte

'clear screen
SEROUT 15,84,1,[noparse][[/noparse]83,0]
PAUSE 1600
main:


· RANDOM color
· color = color//14
· RANDOM xpos
· xpos = xpos//188
· RANDOM ypos
· ypos=ypos//255

'random color,postion sqaure
SEROUT 15,84,1,[noparse][[/noparse]67,31,COLOR,XPOS,YPOS]
PAUSE 17
GOTO main


thank's Brian

Post Edited (truckwiz) : 10/22/2006 1:54:17 PM GMT

Unsoundcode

Hi Brian, I would probably generate the random numbers like this

color VAR Byte
xpos VAR Byte
ypos VAR Byte
rnd VAR Word
'clear screen
SEROUT 15,84,1,[noparse][[/noparse]83,0]
PAUSE 1600
main:
· RANDOM rnd
· color = rnd//14
· RANDOM rnd
· xpos = rnd//188
· RANDOM rnd
· ypos = rnd//255
'random color,postion sqaure
SEROUT 15,84,1,[noparse][[/noparse]67,31,COLOR,XPOS,YPOS]
PAUSE 17
GOTO main

it would still work if you left out the last two RANDOM statements but I think the way it is has the edge in my opinion.

Jeff T.

[Deleted User]

AWSOME·JEFF!!! , works perfect

Thanks ,Brian

Paul Baker

Sorry I wasn't clearer Brian, RANDOM uses a feedback mechanism were the value of a variable before calling RANDOM is used to generate the next value. So this core variable once initialized shouldn't be written to by any other operation besides another RANDOM. So you make a copy of the variable before manipulating it with the modulo or any other operation.

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.

[Deleted User]

paul , I noticed that if you look at the if....then statement in the stamp software it uses random in that way , if I had only dug a little deeper , oh well it's works great now !!!

Thank's
Brian