## What is a matrix in MATLAB?

A matrix is a two-dimensional array of numbers. In MATLAB, you create a matrix by entering elements in each row as comma or space delimited numbers and using semicolons to mark the end of each row.

### What is matrix indexing in MATLAB?

Matrix Indexing in MATLAB. Indexing into a matrix is a means of selecting a subset of elements from the matrix. MATLAB® has several indexing styles that are not only powerful and flexible, but also readable and expressive. Indexing is a key to the effectiveness of MATLAB at capturing matrix-oriented ideas in understandable computer programs.

#### What is the DBSCAN algorithm?

The DBSCAN algorithm identifies three kinds of points: Core point — A point in a cluster that has at least minpts neighbors in its epsilon neighborhood Border point — A point in a cluster that has fewer than minpts neighbors in its epsilon neighborhood

**What are core and border points in DBSCAN?**

Core point — A point in a cluster that has at least minpts neighbors in its epsilon neighborhood Border point — A point in a cluster that has fewer than minpts neighbors in its epsilon neighborhood DBSCAN works with a wide range of distance metrics, and you can define a custom distance metric for your particular application.

**What is MATLAB?**

MATLAB is an abbreviation for “matrix laboratory.” While other programming languages mostly work with numbers one at a time, MATLAB® is designed to operate primarily on whole matrices and arrays. All MATLAB variables are

## What is a radargram in GPR?

GPR data are usually recorded from a number of spatial positions by dragging the antennas along the surface of the ground or walls. A transmit and receive occur at each of the observation positions. The recorded data are then combined to form an image, the radargram.

### How were the radargrams filtered?

Both radargrams were filtered using the processing sequences described in Table 1. The radargrams are shown from the upstream side and the arches are named from the left to the right margin ( Fig. 2) following the usual nomenclature.