RND Range

[honky]

Good morning,
How to have a random number between a minimum and a maximum ?
Thank you for.

[tsh73]


print "N", "[0..10)", "[-10..10)", "-10..10 floating point"
for i = 1 to 15
   print i, random(10), randRange(-10,10), randRangeF(-10,10)
next

'*****************************************************
'function returns a random integer in range [Min, Max)
function randRange(Min, Max)
   randRange = Min +  random(Max-Min)
end function

'*****************************************************
'function returns a random integer in range [0, n)
function random(n)
   random = int(rnd(1)*n)
end function

'*****************************************************
'floating point [Min, Max)
function randRangeF(Min, Max)
   randRangeF = Min +  rnd(0)*(Max-Min)
end function




[honky]

Thank you very much

[plus]

Random Center Weighted
'Random Center Weighted
Dim n(1000)
For i = 0 To 10000
   r = Int(rndCW(50, 50))
   n(r) = n(r) + 1
Next
For i = 0 To 100 Step 4
   For j = 0 To Int(n(i) / 10)
       Print "X";
   Next
   Print
Next

Function rndCW (C, range) 'C = center +/-range weights to center
   rndCW = C + Rnd(1) * range - Rnd(1) * range
End Function


[honky]

I take everything.
Thank you.

[tenochtitlanuk]

For many simulations a useful 'random' is one which is 'normally distributed'. See examples on my LB website..
Dim n( 1000)

For i       = 0 To 10000
   r       = Int( normalVariable( 50, 10))
   n( r)   = n( r) + 1
Next

For i = 0 To 100 Step 4
   For j = 0 To Int( n( i) / 10)
       Print "X";
   Next
   Print
Next

end

function normalVariable( mean, sd)
   pi              =atn( 1) *4
   normalVariable  =mean +sd *( sqr( -2 * log( rnd( 0))) * cos( 2 * pi * rnd( 0)))
end function

'X
'X
'X
'X
'X
'X
'XX
'XXXX
'XXXXXXXXX
'XXXXXXXXXXXXXXXXXX
'XXXXXXXXXXXXXXXXXXXXXXXXXX
'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
'XXXXXXXXXXXXXXXXXXXXXXX
'XXXXXXXXXXXXXXXX
'XXXXXXXX
'XXXX
'XX
'X
'X
'X
'X
'X
'X


[honky]

Too complicated.

[marshawn]

May 23, 2023 10:39:50 GMT plus said:

Random Center Weighted

wow B+, now this is a mod

en.wikipedia.org/wiki/Central_limit_theorem

[plus]

May 24, 2023 10:53:35 GMT honky said:

Too complicated.

Nawh nearly the same as Center Weight, only better! a more natural distribution around the mean instead of Center and 1 standard deviation X 3 might be the range substitute.

Update: john's mean and sd have problems with negative numbers like when sd is too broad. eg r = Int( normalVariable( 50, 15))
No just doesn't work in this demo because in JB arrays don't do negative indexes.