Rescaling with plyr (ddply) in R

Question

I\'ve got this csv table for which I need to rescale data between 0 and 1 per each column. That is, the lowest value of any given column will be 0, the highest will be 1, and al

Answer 1

What about using ifelse to select the scaling direction, based on the value of variable:

tableau.m = ddply(tableau.m, .(variable), transform,
                  rescale = ifelse(variable=="B", 
                                   rescale(value, to=c(1,0)), rescale(value)))

   Net variable value    rescale
1    a        B  1.88 1.00000000
2    b        B  2.05 0.32000000
3    c        B  2.09 0.16000000
4    d        B  2.07 0.24000000
5    e        B  2.13 0.00000000
6    a        C  0.15 0.00000000
7    b        C  0.23 0.21621622
8    c        C  0.29 0.37837838
9    d        C  0.52 1.00000000
10   e        C  0.30 0.40540541
11   a        D  0.60 1.00000000
12   b        D  0.51 0.72727273
13   c        D  0.40 0.39393939
14   d        D  0.36 0.27272727
15   e        D  0.27 0.00000000
16   a    E..e. 10.00 0.04109589
17   b    E..e. 55.00 0.65753425
18   c    E..e. 58.00 0.69863014
19   d    E..e. 80.00 1.00000000
20   e    E..e.  7.00 0.00000000
21   a    F..f. 90.00 1.00000000
22   b    F..f. 80.00 0.00000000
23   c    F..f. 88.00 0.80000000
24   d    F..f. 84.00 0.40000000
25   e    F..f. 90.00 1.00000000