[R] quantiles and dataframe

[Anders Bjørgesæter]

Hi

I have a dataframe, RQ, like this:

A    B1    B2    B3
1    NA    112    12
2    NA    123   123
3    NA    324    13
4    3     21    535
5    4     12    33
6    7     1     335
7    4     NA    3535
8    4     NA    NA
9    NA    NA    NA
10    5    NA    NA
12    4    NA    NA
15    2    NA    NA
17    3    NA    1
63    1    NA    1
75    NA   NA    NA
100   NA   NA    NA
123   NA   NA    NA
155   NA   NA    NA
166   NA   NA    NA
177   NA   NA    NA

I want to extract min, max, 5% and 95% from A based on the range of the Bs.

Using this:

s1<-A[min(which(!is.na(B1))):max(which(!is.na(B1)))]
q1<-quantile(s1,probs=c(0,5,95,100,NA)/100)

I manage to get this by changing the B1 manually for each B

B1    B2    	B3
4.0    1.00     1.00    (min)
63.0   6.00  	63.00   (max)
4.5    4.5      1.65    (5%)
40.0   6.00     63.00   (95%)

I tried to use apply like this: s1<-apply(RQ,2,function(x) 
{A[min(which(!is.na(RQ[,2:4]))):max(which(!is.na(RQ[,2:4])))] })

to get the range of each B but that doesn't work.

Also as you see, s1 includes the A where the B's are NA, e.g. for B1 I 
get the 9 at row 9 (4,5,6,7,8,9,10,12,15,17,63) and not 
(4,5,6,7,8,10,12,15,17,63), which I would prefer.

BUT the main question is how can I extract min, max etc. from each B in 
dataframe RQ without using a loop?

Any help is greatly appreciated!

Best Regards
Anders