# Re: [R] Newbie to R: would like to solve a problem

From: Shawn Mikula <brainmaps_at_gmail.com>
Date: Sat 13 May 2006 - 05:39:31 EST

Using R for this would be a bit bone-headed since it is not ideally suited for web apps. Look at an active scripting language like PHP. I'm not sure if Geocities provides for server-side active scripting languages, in which case you will have to host your site elsewhere.

• Original Message ----- From: "percy tiglao" <prtiglao@gmail.com> To: <r-help@stat.math.ethz.ch> Sent: Friday, May 12, 2006 11:07 AM Subject: [R] Newbie to R: would like to solve a problem

> Hello, I am very new to R (read the introduction a few hours ago), but
> experianced in several other languages (including Scheme, C, ObjC and
> C++, Java and Javascript) and I was wondering how to approach this
> problem:
>
> I am making a training calculator for a Video Game I play. Basically,
> I want to calculate the probability of killing an enemy within x hits,

> to help determine which is the best monster to train on in this game.
>
> The current implementation
> (
http://geocities.com/dragontamer5788/maple2.html) uses the normal
> curve to estimate just about everything. Not necessarily a bad idea
> for when it takes 10 or 15 hits to destroy a single enemy, Central
> Limit Theorm kicks in and normal curve is probably a good idea, but my
> gut feeling is that it is not accurate for estimating kills in 1 or 2
> shots (which happens in the majority of "training" monsters), or the
> probability of Knockback (which is always determined by a single
> shot).
>
> The (simplified) function to represent the damage would be:
>
> sdmg <- function(min, max, skill){
> if(runif(1) > .4) (runif(1) * (max-min) + min) * skill
> else (runif(1) * (max-min) + min) * (skill+1)
> }
>
> total_damage <- function(min, max, skill, num_attacks){
> total <- 0
> for(i in 1:num_attacks){
> total <- total + sdmg(min, max, skill)
> }
> total
> }
>
> --------------------
>
> The above is how damage is calculated. So the probability distribution
> looks like 2 rectangles next to each other, one with height .6 and the
> other with height .4. Sdmg is a helper function, because some attacks
> attack 2 or 4 times in a single turn.
>
> Though, I dont want the simulation (what I'm doing with the runif
> here). I'd like to calculate the probability distribution of
> total_damage, total_damage + total damage (the convolution,
> representing 2 hits), and so on till about 5-8 hits (then I can just
> use normal curve in the web-calculator I'm making), then have a
> polynomial function estimate the probability distributions based on
> min, max, and skill. (So I can make my online calculator estimate the
> probability of killing enemies)
>
> Erm, I know it is a lot to ask for, but how would I go about making
> this in R? And if R isn't the right tool for this, is there any other
> tool you'd reccomend? Cause doing convolutions by hand sucks.
>
> Thanks a lot for reading this long message :) And thanks in advance
>
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