Interface to lp_solve linear/integer programming system
lp (direction = "min", objective.in, const.mat, const.dir, const.rhs,
transpose.constraints = TRUE, int.vec, presolve=0, compute.sens=0,
binary.vec, all.int=FALSE, all.bin=FALSE, scale = 196, dense.const,
num.bin.solns=1, use.rw=FALSE, timeout = 0L)An lp object. See lp.object for details.
Character string giving direction of optimization: "min" (default) or "max."
Numeric vector of coefficients of objective function
Matrix of numeric constraint coefficients, one row per constraint, one column per variable (unless transpose.constraints = FALSE; see below).
Vector of character strings giving the direction of the constraint: each value should be one of "<," "<=," "=," "==," ">," or ">=". (In each pair the two values are identical.)
Vector of numeric values for the right-hand sides of the constraints.
By default each constraint occupies a row of const.mat, and that matrix needs to be transposed before being passed to the optimizing code. For very large constraint matrices it may be wiser to construct the constraints in a matrix column-by-column. In that case set transpose.constraints to FALSE.
Numeric vector giving the indices of variables that are required to be integer. The length of this vector will therefore be the number of integer variables.
Numeric: presolve? Default 0 (no); any non-zero value means "yes." Currently ignored.
Numeric: compute sensitivity? Default 0 (no); any non-zero value means "yes."
Numeric vector like int.vec giving the indices of variables that are required to be binary.
Logical: should all variables be integer? Default: FALSE.
Logical: should all variables be binary? Default: FALSE.
Integer: value for lpSolve scaling. Details can be found in the lpSolve documentation. Set to 0 for no scaling. Default: 196
Three column dense constraint array. This is ignored if const.mat is supplied. Otherwise the columns are constraint number, column number, and value; there should be one row for each non-zero entry in the constraint matrix.
Integer: if all.bin=TRUE, the user can request up to num.bin.solns optimal solutions to be returned.
Logical: if TRUE and num.bin.solns > 1, write the lp out to a file and read it back in for each solution after the first. This is just to defeat a bug somewhere. Although the default is FALSE, we recommend you set this to TRUE if you need num.bin.solns > 1, until the bug is found.
Integer: timeout variable in seconds, defaults to 0L which means no limit is set.
Sam Buttrey, buttrey@nps.edu
This function calls the lp_solve 5.5 solver. That system has many options not
supported here. The current version is maintained at
https://lpsolve.sourceforge.net/5.5/
Note that every variable is assumed to be >= 0!
lp.assign, lp.transport