University of Florida Homepage

Format of data for LP

Format of data for LP’s in standard form:
min c’x subject to Ax = b, lobnd <= x <= upbnd name - problem name (same as mps name card) m - number or rows (input) n - number of columns (input) Ap - pointers to the begining of storage of column (size n+1) Ai - row indices for each non zero entry (input, nnz A) Ax - non zero entries (input, nnz A) b - right hand side (input, size m) c - objective vector (minimize, size n) z0 - initial fixed value for objective lobnd - lower bounds on variables (size n) upbnd - upper bounds on variables (size n) Note: Matrix is stored by columns in Fortran format where the (1,1) element is in column 1 and row 1 (rather than C format where it is in column 0 and row 0). Ap (j) = location of start of column j Ai (Ap (j)) through Ai (Ap (j+1)-1) are the row indices in column j Ax (Ap (j)) through Ax (Ap (j+1)-1) are the numerical values in column j read(file,'(a8)') name read(file,*) m,n read(file,*) (ia(i),i=1,n+1) read(file,*) (ja(i),i=1,ia(n+1)-1) read(file,*) (a(i),i=1,ia(n+1)-1) read(file,*) (b(i),i=1,m) read(file,*) (c(i),i=1,n) read(file,*) z0 read(file,*) (lobnd(i),i=1,n) read(file,*) (upbnd(i),i=1,n)