Falacy's Site - Adding to /list with prob()

Adding to /list with prob() in Developer Help

ID:159514

Feb 24 2009, 7:34 pm

Is there an internal way to add something to a list with a preset probability for use in pick()? I need to be able to add things to a list with a certain probability as I loop through them, and then have it pick one. I can code something for it myself if there isn't already something internal for it, I'm just wondering... ex:

world<<pick(prob(10);"10",prob(20);"20")   //what can be done.

var/list/L=list()
for(var/v=10 to 20 step 10)
    L.Add(prob(v);"[v]")   //something like what I need
world<<pick(L)

#1 Feb 24 2009, 7:38 pm

Kaioken

Nah, it wouldn't make sense to have some probability feature built specifically into adding to lists or something. Provided I gather what you're trying to do correctly, um, can't you simply do this?

if(prob(x)) L += "[x]"

#2 Feb 24 2009, 7:41 pm

In response to Kaioken (#1)

Falacy

Kaioken wrote:

Nah, it wouldn't make sense to have some probability feature built specifically into adding to lists or something. Provided I gather what you're trying to do correctly, um, can't you simply do this?

if(prob(x)) L += "[x]"

Possibly, but then I could end up with an empty list even if there was something to pick from.
What I'm doing more exactly: Looking at all enemies in oview(), adding them to a list, then choosing one to attack, enemies with a higher threat level get targeted more often.

#3 Feb 24 2009, 7:47 pm In response to Falacy (#2)
Kaioken	Looks like what you need is a pickweight() proc, then.

#4 Feb 24 2009, 7:54 pm (Edited on Feb 24 2009, 8:02 pm)

In response to Kaioken (#3)

Falacy

Kaioken wrote:

Looks like what you need is a pickweight() proc, then.

I didn't really read all that, but here's what I'm doing now: (in general)

proc/ThreatPick(var/list/L)
    var/list/IndexList=list()
    var/CurIndex=0
    for(var/obj/O in L)
        CurIndex+=1
        for(var/i=1;i<=O.ThreatLevel;i++)    IndexList+=CurIndex
    return pick(IndexList)

Then using the returned index to reference an actual Troop obj in the original list. Threat levels vary from 1 to 10.

#5 Feb 24 2009, 8:04 pm In response to Falacy (#4)
Kaioken	Falacy wrote: I didn't really read all that You just need to press CTRL-F and read some bits about `pickweight()`, not the whole article.

#6 Feb 24 2009, 8:06 pm In response to Kaioken (#5)
Falacy	Kaioken wrote: You just need to press CTRL-F and read some bits about `pickweight()`, not the whole article. Done already, probably more efficient Lummox's way; since it may loop less depending on list size and threat level.