Five matrices extracted from runs of the chemical engineering package SPEED UP. In each case, the matrix is the initial Jacobian approximation for a sparse nonlinear equation modeling a chemical process system.

Unsymmetric with many zeros on the diagonal. Some of the entries actually have the value zero. This happens when a procedure is used in which all outputs are incorrectly assumed to be a function of all inputs.

These matrices can be significantly reduced by block triangularization methods.

Matrices in this set:

IMPCOL A (real unsymmetric, 207 by 207, 572 entries), Heat exchanger network

IMPCOL B (real unsymmetric, 59 by 59, 312 entries), Cavett's process

IMPCOL C (real unsymmetric, 137 by 137, 411 entries), Ethylene plant model

IMPCOL D (real unsymmetric, 425 by 425, 1339 entries), Nitric acid plant model

IMPCOL E (real unsymmetric, 225 by 225, 1308 entries), Hydrocarbon separation problem