| Author |
Comment/Response |
David
|
 09/20/08 3:47pm
Hello. I am using Mathematica to collapse my data.
Below is my data.
A B C D E F
1 1 1 0.1 23 2
2 1 1 0.1 45 3
3 1 1 0.1 56 5
4 1 1 0.1 74 6
5 1 1 0.1 43 8
1 1 2 0.2 45 54
2 1 2 0.2 45 4
3 1 2 0.2 32 3
4 1 2 0.2 46 5
5 1 2 0.2 57 78
1 2 1 0.3 56 5
2 2 1 0.3 48 3
3 2 1 0.3 34 5
4 2 1 0.3 75 78
5 2 1 0.3 34 5
1 2 2 0.4 67 3
2 2 2 0.4 35 4
3 2 2 0.4 37 4
4 2 2 0.4 47 4
5 2 2 0.4 26 54
A = {1,2,3,4,5} and this set is repeated four times. B,C,D are systematically sorted. E is the outcome variable which is my major interest. F is an irrelevant variable.
Here are my questions.
(1) How do I sort the data by the ascending(or descending) order of B or C or D? For example, when B is being sorted, the corresponding values of other variables should be moved following the order of B.
(2) I want to select all the variables except F.
I could simply drop the F column. But instead of doing so, could somebody tell me how to just select A,B,C,D,E.
(3) Then, I want to collapse my data. Because A consists of four sets and each set has five lines in which all the values of B(C, D too) are same.
I want to condense the 20 lines into 4 lines such like the following table.
A B C D E
1 1 1 0.1 (23+45+56+74+43)/5
2 1 2 0.2 (45+45+32+46+57)/5
3 2 1 0.3 (56+48+34+75+34)/5
4 2 2 0.4 (67+35+37+47+26)/5
Here A now represents four sets.
In each set B, C, D have only one value as you saw in the previous table.
The trickiest thing is E. I want to record the mean of five values(in each set) of E in the new table. This is a real challenge to me.
Because I have a really really huge data, this is the only way I can deal with this data. Luckily, the data has some orders.
Many thanks in advance.
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