I'm working on a binary integer programming assignment and I was hoping there would be a short cut to typing in all the ones and zeros for the constraints. I created two matrices. The first contains all zeros and the second contains all ones.
I have 34 variables and created two matrices like this (though I may not have needed to created these):
zero_constraints = matrix(data = 0, nrow = 1, ncol = 34)
one_constraints = matrix(data = 1, nrow = 1, ncol = 34)
Here's an example of the constraints:
# He therefore decides to include only one collage.
filter(data_raw, data_raw$Medium.Style == "Collage")$ID
output:
[1] 9 16 29 30
I gave each variable a number so these numbers would mean I needed variables 9, 16, 29, and 30 to be 1 and the rest of my variables to be 0.
This where I get lost:
one_constraints[, c(filter(data_raw, data_raw$Medium.Style == "Collage")$ID)]
I know the line above gets me the "ones" I need from my matrix of 34 ones so then I tried to concatenate my two matrices of ones and zeroes:
cat(
one_constraints[, c(filter(data_raw, data_raw$Medium.Style == "Collage")$ID)],
zero_constraints[, -c(filter(data_raw, data_raw$Medium.Style == "Collage")$ID)]
)
output:
1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
but this is not the desired output. The ones should not be in a row at the beginning. It should look something like this:
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0
If this is too complicated, I can just go with my initial plan to cbind matrices, which is how I created the above.
If you want that code:
cbind(
matrix(data = 0, nrow = 1, ncol = 8), # 1-8
1, # 9
matrix(data = 0, nrow = 1, ncol = 6), # 10-15
1, # 16
matrix(data = 0, nrow = 1, ncol = 12), # 17
1, 1, # 29, 30
matrix(data = 0, nrow = 1, ncol = 4) # 31-34
)
Edit I tried this answer:
inds <- c(9, 16, 29, 30)
mat <- matrix(0, ncol = 34)
mat[, inds] <- 1
by doing this:
twnety_one_con <- filter(data_raw, data_raw$Medium.Style == "Collage")$ID
twnety_one_mat <- matrix(data = 0, nrow = 1, ncol =34)
mat <- (twnety_one_mat[, twnety_one_mat] <- 1)
I may be doing it wrong but it doesn't work. It returns a vector of 1 and when I put it my add.constraint bit of code it confirms that it doesn't match vector length
In the OP's function, the index from filter step returns the 'ID's which represents the column index. We only need to assign (<-) the values to 1
inds <- c(9, 16, 29, 30)
mat <- matrix(0, ncol = 34)
mat[, inds] <- 1
mat
# [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13] [,14] [,15] #[,16] [,17] [,18] [,19] [,20] [,21] [,22] [,23] [,24]
#[1,] 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 #1 0 0 0 0 0 0 0 0
# [,25] [,26] [,27] [,28] [,29] [,30] [,31] [,32] [,33] [,34]
#[1,] 0 0 0 0 1 1 0 0 0 0