Hi guys,
As the title show, I want to spawn different items but not just randomly. For instance in my case I have bunch of items that the player need to collect (runner game) but some are more precious than others so I do not want to spawn them with same probability. So I want to spawn cheaper items more often than items that are more precious and should be spawn much less often.
I have to admit that my math skill are very rusty:)
Thanks for any suggestions.
Mo
www.j-strahan.com
go to freebies download js.lua
it has code to weight the results to be more lower or higher number
Thanks a lot! I will Check it out. Mo
look under downloads and activate.lua its an updated version
mRandom = math.random(1,10); if(mRandom == 1 or mRandom == 2)then --do something end
Probability: 2/10=1/5
@iStrahan: Thanks. The gameLog alone deserve a donation! Cool stuff!
@LavitzBr: Thanks a lot. That’s what I am basically doing. I just wanted a more “algorithmic” way of doing that 
I also found this on Stackoverflow:
Assuming that you have a function p(n) that gives you the desired probability for a random number:
r = rand() // a random number between 0 and 1
for i in A to B do
if r < p(i)
return i
r = r - p(i)
done
A and B are the range of the random number you want (ie: A = 1, B =10) I guess p(n) is an array where you need to fill up with each category probability like:
p(1) = 0.5 – 50% chance for spawning a red ball
p(2) = 0.25 – 25% “”" yellow ball
p(3) = 0.05 – 5% “” green ball
p(4P = 0.02 – 2% “” blue ball
At least that’s the way I read it.
I guess in Lua, we could do something like this (NOT TESTED):
[lua]
p = {0.5,0.25,0.05,0.02}
A= 1
B =10
local function chance (A,B)
r = math.random()
for i = A,B do
if r < p(i) then
return i
else
r = r - p(i)
end
end
[/lua]
Please let me know if you see any errors!
Thanks a lot again guys. I think these time of random generation makes game more fun since you control how often an activity (enemies, powerups…) is generated.
Mo
thx Mo
appLig is old I have a newer version called blackBox that’s a lot better more options but not ready for download. if you want I’ll send you a copy. you may need to make a few change to make it work with graphics2.0 I plan to convert it but trying to finish what I’m working on right now
www.j-strahan.com
go to freebies download js.lua
it has code to weight the results to be more lower or higher number
Thanks a lot! I will Check it out. Mo
look under downloads and activate.lua its an updated version
mRandom = math.random(1,10); if(mRandom == 1 or mRandom == 2)then --do something end
Probability: 2/10=1/5
@iStrahan: Thanks. The gameLog alone deserve a donation! Cool stuff!
@LavitzBr: Thanks a lot. That’s what I am basically doing. I just wanted a more “algorithmic” way of doing that
I also found this on Stackoverflow:
Assuming that you have a function p(n) that gives you the desired probability for a random number:
r = rand() // a random number between 0 and 1
for i in A to B do
if r < p(i)
return i
r = r - p(i)
done
A and B are the range of the random number you want (ie: A = 1, B =10) I guess p(n) is an array where you need to fill up with each category probability like:
p(1) = 0.5 – 50% chance for spawning a red ball
p(2) = 0.25 – 25% “”" yellow ball
p(3) = 0.05 – 5% “” green ball
p(4P = 0.02 – 2% “” blue ball
At least that’s the way I read it.
I guess in Lua, we could do something like this (NOT TESTED):
[lua]
p = {0.5,0.25,0.05,0.02}
A= 1
B =10
local function chance (A,B)
r = math.random()
for i = A,B do
if r < p(i) then
return i
else
r = r - p(i)
end
end
[/lua]
Please let me know if you see any errors!
Thanks a lot again guys. I think these time of random generation makes game more fun since you control how often an activity (enemies, powerups…) is generated.
Mo
thx Mo
appLig is old I have a newer version called blackBox that’s a lot better more options but not ready for download. if you want I’ll send you a copy. you may need to make a few change to make it work with graphics2.0 I plan to convert it but trying to finish what I’m working on right now