## Introduction

MARPLE package is designed under the ARTE frame.

The idea of this package is to provide a common tool to work with different objects to be matched such as segments, clusters, tracks ( probably even hits or vertexes). To provide such tool which is independent on the features of the other reconstruction packages of ARTE the MARPLE is based on the "object oriented" philosophy and written on C++ .

The special MARPLE class RcPoint contains a common information provided/used by these modules such as coordinates( $x, y, z$), slopes ( $tx = p_x / p_z, ty = p_y / p_z$ ), momentum information ( charge over momentum ($Q/p$) or energy deposited in the ECAL) and covariant matrix of these parameters. The RcPoint class provides also the standard reconstruction operations: Kalman formalism, linear and Runge-Kutta methods for the prolongation through the detector, techniques to take into account a multiple scattering and refit of the parameters. More features are added by using derived classes ( see section RcPoint class Family )

Two RcPoint objects could be matched by RcMatchPoint class. The parameters of match are passed by RcMatchConst structure. This structure contains also switches of the cuts which could be used during matching. The quality of the match $\chi^2$ is obtained by the method of least squares. The RcMatchBuilder template class provides a default match algorithm which works with two sets ( vectors) of the RcPoints to be matched. In case the standard MARPLE classes of the RcPoint class Family with relation to the ARTE banks RSEG/RTRA/RCCL are used the RcMatchBuilder saves found relations of objects to ARTE table.

The regular structure of package allows user to take control over any subunits of the whole process. Using the C++ advantages the nonstandard operations and algorithms could be applied during match. MARPLE package contains also some tools for the optimization of the match procedure for the concrete case. As an Example the match of segments reconstructed in SVD (e.g. by CATS) and in Main Tracker area (e.g. by RANGER) is presented. A set of Supplied Products presents a match of general interest.

Olya Igonkina November-2001

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