R: make H-representation of convex polyhedron

makeH {rcdd}

R Documentation

make H-representation of convex polyhedron

Description

Construct H-representation of convex polyhedron, set of points x satisfying

    a1 %*% x <= b1
    a2 %*% x == b2

see scdd for description of valid representations.

Usage

makeH(a1, b1, a2, b2, x = NULL)
addHeq(a, b, x)
addHin(a, b, x)

Arguments

`a1`	numerical matrix for inequality constraints. If vector, treated as matrix with one row.
`b1`	numerical right hand side vector for inequality constraints.
`a2`	numerical matrix for equality constraints. If vector, treated as matrix with one row.
`b2`	numerical right hand side vector for equality constraints.
`x`	if not `NULL`, a valid H-representation.
`a`	numerical matrix for constraints. If vector, treated as matrix with one row. Constraints are equality in `addHeq` and inequality in `addHin`.
`b`	numerical right hand side vector for constraints.

Arguments a1, b1, a2, and b2 may be missing, but must be missing in pairs. Rows in x, if any, are added to new rows corresponding to the constraints given by the other arguments.

Value

a cdd object that can be handed to scdd.

Examples

d <- 4
# unit simplex in H-representation
qux <- makeH(- diag(d), rep(0, d), rep(1, d), 1)
print(qux)
# add an inequality constraint
qux <- addHin(c(1, -1, 0, 0), 0, qux)
print(qux)
# drop a constraint
qux <- qux[- 3, ]
print(qux)