CODEWITHSUNDEEP
rloopsdataframe
mql4beginner
mql4beginner

Reputation: 2243

How to add data frame's Interaction calculated variables into a new formula

I need to insert new numeric variables that are Interactions of the data frame's variables.I managed to it manually by calling the variables by names but how can I do it without calling them by thier names? 

 dat <- read.table(text = " IndexRow TargetVar  chairs    tables     lamps  vases
    1     0        0        0         7  9
    2     0        0        1         1  6 
    3     0        1        0         3  5 
    4     0        1        1         7  8 
    5     1        0        0         5  4
    6     1        0        1         1  3 
    7     1        1        0         0  7
    8     1        1        1         6  6
    9     0        0        0         8  9  ", header = TRUE)

If I enter the variables manually the following line of code will work as expected: dat<-cbind(dat,data.frame(model.matrix(~(chairs+ tables)^2-1,dat))) But I can't figuring out how to insert the variables without calling them by thier names. I tried the following two lines of code with out success, Any Ideas how to solve this issue?
try1:

dat<-model.matrix(~(dat[,1:ncol(dat)])^2-1,data =dat )

try2:

e<-for (i in names(dat)) function(x) {model.matrix(~(dat[,i])^2-1,dat[,i])}

Upvotes: 0

Views: 603

Answers (1)

Roland
Roland

Reputation: 132969

Subset the data.frame and then create main factors and first-order interactions from all variables:

as.data.frame(model.matrix(~ (. + .)^2 - 1, dat[, 3:5]))
#  chairs tables lamps chairs:tables chairs:lamps tables:lamps
#1      0      0     7             0            0            0
#2      0      1     1             0            0            1
#3      1      0     3             0            3            0
#4      1      1     7             1            7            7
#5      0      0     5             0            0            0
#6      0      1     1             0            0            1
#7      1      0     0             0            0            0
#8      1      1     6             1            6            6
#9      0      0     8             0            0            0

Upvotes: 2

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