The Classification Scheme

The Classification Scheme was proposed in [Bus, 1977], [Hock and Schittkowski, 1981], [Bongartz et al., 1993], [Conn et al., 1992].

Global optimization problem is classified by the string

OCSD-KI-n-m or OCSD-KIT-n-m,


O = objective code:

Possible values are:

C = Constant

L = Linear

N = No objective

Q = Quadratic

S = Sum of squares

O = Other (none of the above)

C = constraint type:

Possible values are:

B = Bounds on variables

L = Linear

N = linear Network

Q = Quadratic

U = Unconstrained

X = just fiXed variables

P = Polynomial   (new)

T = Trigonometric (new)

O = Other (none of the above)

S = smoothness:

Possible values are:

R = Twice continuously differentiable

I = Other

D = degree of available derivatives: always 2 here; 0, 1, or 2 in general

K = kind of the problem:

Possible values are:

A = Academic

M = Modeling

R = Real application

I = internal variables:

Y = yes, problems has useful internal variables

N = no useful internal variables

  T = Type of solution set:   (new)

Possible values are:

 I = Isolated

N = Non-isolated

U = Unknown

n = number of variables; V (varies) - the number of variables in the problem can be chosen by the user,

m = number of constraints; V (varies) - the number of variables in the problem can be chosen by the user,


This string does not contain any blanks.


[Bongartz et al., 1993] I. Bongartz, A.R.Conn, N. Gould and Ph.L.Toint. CUTE: Constrained and unconstrained testing environment Report 93/10 (revised). Department of Mathematics, Facultes Universitaires ND de la Paix, Namur, Belgium, 1993.

[Bus, 1977] J.C.P. Bus. A proposal for the classification and documentation of test problems in the field of nonlinear programming. Technical report, Mathematisch Centrum, Amsterdam, 1977.

[Conn et al., 1992] A.R. Conn, N.I.M. Gould, and Ph.L. Toint. LANCELOT: a Fortran package for large-scale nonlinear optrimization (Release A). Number 17 in Springer Series in Computational Mathematics. Springer Verlag, Heidelberg, Berlin, New York, 1992.

[Hock and Schittkowski, 1981] W. Hock and K. Schittkowski. Test Examples for Nonlinear Programming Codes. Springer Verlag, Berlin, 1987. Lectures Notes in Economics and Mathematical Systems 282.