[R] Percentiles in R

[Jose Luis Aznarte M.]

    Thank you all! But the problem is that quantile() returns "how many 
data" are greater than p percent, and not a value in the domain of the 
vector under scrutiny. For example, I have a vector

 > x
 [1] "-0,39559"  "1,1916"    "0,23214"   "1,656"     "-0,3439"   "-0,50568"
 [7] "0,52281"   "0,96209"   "0,0087242" "-0,030727" "1,0935"    "0,35159" 
[13] "0,79229"   "0,81791"   "0,3186"    "1,0165"    "0,65567"   "-0,56474"
[19] "-0,34662"  "0,70435"   "-0,73285"  "-0,60452"  "-0,92526"  "-0,296"  
[25] "0,51298"   "0,38654"   "0,32469"   "-0,92555"  "0,53023"   "0,050059"
[31] "1,09"      "-0,35462"  "0,37674"   "1,1409"    "0,072098"  "1,4234"  
[37] "1,43"      "0,68532"   "0,078089"  "0,61944" 

and, if I want to see the 10th percentile, in Matlab I go

 >> prctile(x, 10)
ans =
   -0.4067

But in R:

 > quantile(x, probs=.1)
 10%
51.5

I need to obtain -0.4067, do you see what I mean? Thanks a lot again!!

Jose Luis Aznarte M. escribió:
> Hi there! Still struggling to translate Matlab code into R's tsDyn package.
> Here is my question: Is there in R an equivalent function to Matlab's 
> prctile()? To the moment I thought it was quantile(), but I just 
> realized I was wrong. The definition of the Matlab function:
>
> prctile
> Percentiles of a sample
> SyntaxY = prctile(X,p)
> Description
> Y = prctile(X,p) calculates a value that is greater than p percent of 
> the values in X. The values of p must lie in the interval [0 100]. For 
> instance, if p = 50 then Y is the median of X
>
> Thanks!!
>
>   


-- 
--                                                      --
Jose Luis Aznarte M.       http://decsai.ugr.es/~jlaznarte
Department of Computer Science and Artificial Intelligence
Universidad de Granada           Tel. +34 - 958 - 24 04 67
GRANADA (Spain)                  Fax: +34 - 958 - 24 00 79