Hi R- User,
I am just wondering how I can make a loop to repeat multiple regression.
I do have more than 3000 dependent variables (example S1, S2......Sn) and put in different columns but the explanatory variables are the same for all these dependent variables. I have given an example below. In this example, S1, S2,....Sn are the dependent  variables and; en1_predictor, en2_predictor, en3_predictor are the predictors for the dependent variables.

I wanted to make a multiple regression for each dependent variable using these 4 predictors and make  two tables: table 1 is: predicted value for each dependent variable and; the table 2: is the R2 adjusted  and associated p value of  each model (each dependent variable). 

I have been doing it (multiple regression)  for each dependent variable manually  but taking so much time.  I am just wondering how I can make a loop from which I can extract these information in two tables. 

> dput(dat)
dat<-structure(list(sites = 1:22, S1 = c(4L, 7L, 9L, 10L, 10L, 8L, 
8L, 8L, 17L, 18L, 13L, 13L, 11L, 1L, 10L, 20L, 22L, 20L, 18L, 
16L, 7L, 20L), S2 = c(5L, 8L, 12L, 9L, 12L, 5L, 5L, 7L, 21L, 
12L, 17L, 17L, 10L, 2L, 9L, 21L, 19L, 21L, 15L, 23L, 12L, 18L
), Sn = c(7L, 12L, 23L, 7L, 24L, 9L, 2L, 6L, 19L, 21L, 32L, 12L, 
54L, 12L, 32L, 35L, 21L, 34L, 25L, 27L, 21L, 32L), en1_predictor = c(-2.5767, 
-2.5767, -2.5767, -2.5767, -2.5767, -2.5767, -2.5767, -2.5347, 
-2.5347, -2.5347, -2.5347, -2.5347, -2.5347, -2.4939, -2.4939, 
-2.4939, -2.4939, -2.4939, -2.4939, -2.4939, -2.4543, -2.4543
), en2_predictor = c(-1.1785, -0.6596, -0.6145, -0.6437, -0.6593, 
-0.7811, -1.1785, -1.1785, -1.1785, -0.6596, -0.6145, -0.6437, 
-0.6593, -1.1785, -0.1342, -0.2085, -0.4428, -0.5125, -0.8075, 
-1.1785, -1.1785, -0.1342), en3_predictor = c(-1.4445, -1.3645, 
-1.1634, -0.7735, -0.6931, -1.1105, -1.4127, -1.5278, -1.4445, 
-1.3645, -1.1634, -0.7735, -0.6931, -1.0477, -0.8655, -0.1759, 
0.1203, -0.2962, -0.4473, -1.0436, -0.9705, -0.8953), en4_predictor = c(-0.4783, 
-0.3296, -0.2026, -0.3579, -0.5154, -0.5726, -0.6415, -0.3996, 
-0.4529, -0.5762, -0.561, -0.6891, -0.7408, -0.6287, -0.4337, 
-0.4586, -0.5249, -0.6086, -0.7076, -0.7114, -0.4952, 0.1091)), .Names = c("sites", 
"S1", "S2", "Sn", "en1_predictor", "en2_predictor", "en3_predictor", 
"en4_predictor"), class = "data.frame", row.names = c(NA, -22L
))

Your help is highly appreciated. 
Cheers,
Kristi
=================

 		 	   		  
	[[alternative HTML version deleted]]

