How to get a random DECIMAL value??

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The Slayer

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Posted: 6th Jun 2010 23:10

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Today I tried to get a random value between 0.00 and 0.99, and it doesn't seem to work. The command rnd() returns integer values, I know, but when I divide that value by 100, it doesn't work. This is the code that I've tried:

+ Code Snippet

SYNC ON : SYNC RATE 60
do
cls
C = rnd(99)
C1# = C/10
C2# = C/100
SET CURSOR 0,0
print "C= ", C
print "C/10= ", C1#
print "C/100= ", C2#
if spacekey() then end
sync
loop

So, does anyone know why this doesn't work or how to make it work?

Thanks in advance.

Cheers

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Neuro Fuzzy

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Posted: 6th Jun 2010 23:28

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the operators you're using are still dealing with integers thar.

if you say:
c#=15/10, then c# will be 1, because 15/10 using integer division gives an integer result, 1. saying rnd(9)/10 will always be preforming integer division. Solution? replace "C1# = C/10" with "C1# = C/10.0"

10 is an integer, but 10.0 is a float, and you need a float.

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HowDo

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Location: United Kingdom

Posted: 6th Jun 2010 23:33

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try this, one of your value need a decimal in it to work.

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SYNC ON : SYNC RATE 60
do
cls
C = rnd(99)
C1# = C/10.0
C2# = C/100.0
SET CURSOR 0,0
print "C= ", C
print "C/10= ", C1#
print "C/100= ", C2#
if spacekey() then end
sync
loop

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The Slayer

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Playing: (Hide and) Seek and Destroy on my guitar!

Posted: 6th Jun 2010 23:43

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Thanks guys, that worked!

I thought that just adding the # would do the trick. I was a little confused because I work a lot in Excel lately, and I assumed that dividing by 100 was enough.

Cheers

Slayer rules!!! Yeaaah, man!

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KISTech

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Location: Aloha, Oregon

Posted: 7th Jun 2010 01:14

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c = rnd(99)
t$ = "0." + str$(c)
t = val(t$)
print t

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Digger412

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Posted: 7th Jun 2010 05:38

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@KISTech - You beat me to it x.x

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BatVink

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Posted: 7th Jun 2010 14:54

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don't forget to start with something along the lines of RANDOMIZE TIMER() or you'll get the same random values every time.

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Sasuke

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Location: Milton Keynes UK

Posted: 7th Jun 2010 18:51 Edited at: 7th Jun 2010 19:20

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Just an idea:

+ Code Snippet

randomize timer()

for n = 1 to 20
    print RanFloat( 0.00, 0.99 )
next n
wait key
end

// only to 3 decimal places though
function RanFloat( lower as float, upper as float )
    local out as float : out = (rnd(int((upper*1000.0)-(lower*1000.0)))*0.001)+lower
endfunction out

And with precision:

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randomize timer()

for n = 1 to 20
    print RanFloat( 0.00, 0.99, 4 )
next n
wait key
end

function RanFloat( lower as float, upper as float, precision as byte )
    local power as float : power = 10^precision
    local out as float : out = (rnd(int((upper*power)-(lower*power)))/power)+lower
endfunction out

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DarkBASIC Professional Discussion / How to get a random DECIMAL value??