[R] lm() with same formula but different column/factor combinations in data frame

Murtaza Das murtazadas at gmail.com
Fri Dec 26 18:37:32 CET 2008


Hi,

I am trying to find an efficient way of applying a linear regression
model to different factor combinations in a data frame.
I want to obtain the output with minimal or no use of loops if
possible. Please let me know if this query is unclear.

Thanks,
Murtaza

***********************************************************************************************************************************************************

The data frame TEST1 has four factor columns followed by thirteen
numeric columns defined as :
1) Community, levels: "20232"
2) WT, levels: "B", "E", "M"
3) LTC, levels: "L", "M", "S", "1"
4) UC, levels: "1X1", "2X2"
5) UncDmd: Response variable in the linear model
6-16) M1...M11: Explanatory variables in the linear model

A few sample rows in the data frame are as follows:
> TEST1[1:15,]
   Community WT LTC  UC   UncDmd M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M11
1      20232  E   L 1X1 1.000000  0  0  0  0  0  0  0  0  0   0   1
2      20232  E   L 2X2 0.000000  0  0  0  0  0  0  0  0  0   0   1
3      20232  E   M 1X1 1.000000  0  0  0  0  0  0  0  0  0   0   1
4      20232  E   M 2X2 1.000000  0  0  0  0  0  0  0  0  0   0   1
5      20232  E   S 1X1 0.000000  0  0  0  0  0  0  0  0  0   0   1
6      20232  E   S 2X2 0.000000  0  0  0  0  1  0  0  0  0   0   0
7      20232  B   1 1X1 0.209117  0  0  0  0  0  0  0  0  0   0   1
8      20232  B   1 2X2 0.190605  0  0  0  0  0  0  0  0  0   0   1
9      20232  B   L 1X1 0.000000  0  0  0  0  1  0  0  0  0   0   0
10     20232  B   L 2X2 1.000000  0  0  0  0  0  0  0  0  0   0   1
11     20232  B   M 1X1 4.000000  0  0  0  0  0  0  0  0  0   0   1
12     20232  B   M 2X2 0.000000  0  0  0  0  0  0  0  0  0   0   1
13     20232  B   S 1X1 0.000000  1  0  0  0  0  0  0  0  0   0   0
14     20232  B   S 2X2 0.000000  0  0  0  0  0  0  0  0  0   0   1
15     20232  M   1 1X1 0.618689  0  0  0  0  0  0  0  0  0   1   0

*********************************************************************************************************************************************************
I need to store the coefficients using lm() for different combinations
of the 4 factors, or different combinations of 3 factors or different
combinations of 2 factors or
differennt combinations of 1 factor.
The formula remains fixed as:
> Formula
UncDmd ~ M1 + M2 + M3 + M4 + M5 + M6 + M7 + M8 + M9 + M10 + M11

So, different models I want to solve in R are :
1) Community :                     lm(Formula,TEST1[  as.logical(
(TEST1[[1]]=="20232") ) , ])
2) WT :                            lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="B") ) , ])
3) WT :                            lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="E") ) , ])
4) WT :                            lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="M") ) , ])
5) LTC :                           lm(Formula,TEST1[  as.logical(
(TEST1[[3]]=="L") ) , ])
6) LTC :                           lm(Formula,TEST1[  as.logical(
(TEST1[[3]]=="M") ) , ])
7) LTC :                           lm(Formula,TEST1[  as.logical(
(TEST1[[3]]=="S") ) , ])
8) LTC :                           lm(Formula,TEST1[  as.logical(
(TEST1[[3]]=="1L") ) , ])
9) UC :                            lm(Formula,TEST1[  as.logical(
(TEST1[[4]]=="1X1") ) , ])
10) UC :                           lm(Formula,TEST1[  as.logical(
(TEST1[[4]]=="2X2") ) , ])
11) Community, WT :                lm(Formula,TEST1[  as.logical(
(TEST1[[1]]=="20232") * (TEST1[[2]]=="B") ) , ])
12) Community, WT :                lm(Formula,TEST1[  as.logical(
(TEST1[[1]]=="20232") * (TEST1[[2]]=="E") ) , ])
13) Community, WT :                lm(Formula,TEST1[  as.logical(
(TEST1[[1]]=="20232") * (TEST1[[2]]=="M") ) , ])
14) Community, LTC :               lm(Formula,TEST1[  as.logical(
(TEST1[[1]]=="20232") * (TEST1[[3]]=="L") ) , ])
15) Community, LTC :               lm(Formula,TEST1[  as.logical(
(TEST1[[1]]=="20232") * (TEST1[[3]]=="M") ) , ])
16) Community, LTC :               lm(Formula,TEST1[  as.logical(
(TEST1[[1]]=="20232") * (TEST1[[3]]=="S") ) , ])
17) Community, LTC :               lm(Formula,TEST1[  as.logical(
(TEST1[[1]]=="20232") * (TEST1[[3]]=="1") ) , ])
18) Community, UC :                lm(Formula,TEST1[  as.logical(
(TEST1[[1]]=="20232") * (TEST1[[4]]=="1X1") ) , ])
19) Community, UC :                lm(Formula,TEST1[  as.logical(
(TEST1[[1]]=="20232") * (TEST1[[4]]=="2X2") ) , ])
20) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="B") * (TEST1[[3]]=="L") ) , ])
21) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="B") * (TEST1[[3]]=="M") ) , ])
22) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="B") * (TEST1[[3]]=="S") ) , ])
23) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="B") * (TEST1[[3]]=="1") ) , ])
24) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="E") * (TEST1[[3]]=="L") ) , ])
25) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="E") * (TEST1[[3]]=="M") ) , ])
26) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="E") * (TEST1[[3]]=="S") ) , ])
27) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="E") * (TEST1[[3]]=="1") ) , ])
28) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="M") * (TEST1[[3]]=="L") ) , ])
29) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="M") * (TEST1[[3]]=="M") ) , ])
30) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="M") * (TEST1[[3]]=="S") ) , ])
31) WT, LTC :                      lm(Formula,TEST1[  as.logical(
(TEST1[[2]]=="M") * (TEST1[[3]]=="1") ) , ])
32) WT, UC :
...
...
xx) LTC, UC :
...
xxx) Community, WT, LTC :
...
...
and so on upto:
xxxx) Community, WT, LTC, UC :  lm(Formula,TEST1[  as.logical(
(TEST1[[1]]=="20232") * (TEST1[[2]]=="M") * (TEST1[[3]]=="1") ) *
(TEST1[[4]]=="2X2"), ])
***********************************************************************************************************************************************************
Desired Output format (or something simlar):
  Factor1 Factor2 Factor3 Factor4 Intercept  M1  M2  M3  M4  M5  M6
M7  M8  M9  M10  M11
1) 20232                                            x        x   x
x   x   x   x   x   x   x   x    x
2)           B                                         x        x   x
  x   x   x   x   x   x   x   x    x
3)           E                                         x        x   x
  x   x   x   x   x   x   x   x    x
4)           M                                        x        x   x
 x   x   x   x   x   x   x   x    x
5)                         L                           x        x   x
  x   x   x   x   x   x   x   x    x
6)                        M                           x        x   x
 x   x   x   x   x   x   x   x    x
7)                        S                           x        x   x
 x   x   x   x   x   x   x   x    x
8)                         1                           x        x   x
  x   x   x   x   x   x   x   x    x
9)                                   1X1             x        x   x
x   x   x   x   x   x   x   x    x
10)                                  2X2            x        x   x
x   x   x   x   x   x   x   x    x
11) 20232    B                                   x        x   x    x
x   x   x   x   x   x   x    x
..
..
and so on..


x is the respective coefficient obtained from the linear fit.



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