The vertical concatenation of expressions. This is equivalent to rbind when applied to objects with the same number of columns.
vstack(...)Expression objects, vectors, or matrices. All arguments must have the same number of columns.
An Expression representing the concatenated inputs.
x <- Variable(2)
y <- Variable(3)
c <- matrix(1, nrow = 1, ncol = 5)
prob <- Problem(Minimize(c %*% vstack(x, y)), list(x == c(1,2), y == c(3,4,5)))
result <- solve(prob)
result$value
#> [1] 15
c <- matrix(1, nrow = 1, ncol = 4)
prob <- Problem(Minimize(c %*% vstack(x, x)), list(x == c(1,2)))
result <- solve(prob)
result$value
#> [1] 6
A <- Variable(2,2)
C <- Variable(3,2)
c <- matrix(1, nrow = 2, ncol = 2)
prob <- Problem(Minimize(sum(vstack(A, C))), list(A >= 2*c, C == -2))
result <- solve(prob)
result$value
#> [1] -4
B <- Variable(2,2)
c <- matrix(1, nrow = 1, ncol = 2)
prob <- Problem(Minimize(sum(vstack(c %*% A, c %*% B))), list(A >= 2, B == -2))
result <- solve(prob)
result$value
#> [1] 0