readMps {linprog} | R Documentation |
This function reads MPS files - the standard format for Linear Programming problems.
readMps( file, solve=FALSE, maximum=FALSE )
file |
a character string naming the file to read. |
solve |
logical. Should the problem be solved after reading it
from the file (using solveLP )? |
maximum |
logical. Should we maximize or minimize (the default)? |
Equality constraints and 'greater than'-bounds are not implemented yet.
readMps
returns a list containing following objects:
name |
the name of the Linear Programming problem. |
cvec |
vector c. |
bvec |
vector b. |
Amat |
matrix A. |
res |
if solve is TRUE, it contains the results of the solving
process (an object of class solveLP ). |
Arne Henningsen ahenningsen@agric-econ.uni-kiel.de
## example of Steinhauser, Langbehn and Peters (1992) ## Not run: library( linprog ) ## Production activities cvec <- c(1800, 600, 600) # gross margins names(cvec) <- c("Milk","Bulls","Pigs") ## Constraints (quasi-fix factors) bvec <- c(40, 90, 2500) # endowment names(bvec) <- c("Land","Stable","Labor") ## Needs of Production activities Amat <- rbind( c( 0.7, 0.35, 0 ), c( 1.5, 1, 3 ), c( 50, 12.5, 20 ) ) ## Write to MPS file writeMps( "steinh.mps", cvec, bvec, Amat, "Steinhauser" ) ## delete all LP objects rm( cvec, bvec, Amat ) ## Read LP data from MPS file and solve it. lp <- readMps( "steinh.mps", TRUE, TRUE ) ## Print the results lp$res