### Matrices in Matlab

In the previous tutorial we have used the concept vector. This is a special case of matrix. A two-dimensional matrix is nothing but a rectangular table with its elements ordered in rows and columns. A matrix mxn consists of m rows and n columns. In Matlab this can be written for a matrix A.

>> A= [ 1 2 3; 4 5 6 ] % semicolon separates rows. |

This matrix A has 2 rows and 3 columns. The first row is: 1 2 3 and the second: 4 5 6 . For the columns we have the have following order: Column 1: 1,4 column 2: 2,5 and finally column 3: 3,6

Each entry in the matrix A is accessible by using the following indices:

A(row_index, column_index) |

For instance try the following :

>> A(2,1)+A(2,3)+A(1,1) % adds three elements in A |

or

The most common matrix in matlab is the two-dimensional one. Many of the commands in matlab are only for valid for such matrices. The arithmetic operators (+, -, *, / and ^) that we used in tutorial1 can also be applied for matrices, but we also have some others as well.

#### Exercise 1: Vectors in Matlab

Generate a vector x=[5, -4, 6 ] with three elements. In Matlab as:

or alternatively

>> x(1)=5; x(2)=-4; x(3)=6; |

What is the answer of x(4) and x(0) ?

The indices in a vector starts from 1 and in this case ends with 3. Therefore to ask for x(4) and x(0) is pointless. Suppose we would have done differently creating the vector x. Read more »

Tags: combining matrices, inverse matrix, inverse of a matrix, mathlab tutorial, mathlab tutorials, matlab beginner, matlab codes, matlab courses, matlab examples, matlab exercises, matlab function examples, matlab functions, matlab matrices, matlab matrix operations, matlab samples, matlab tutorial, matrices in matlab, quadratic matrix, transpose, transpose matrix in matlab, zero matrix

Matlab Tutorials | admin, March 24, 2009 2:47 pm | Comments (0)

In this first Matlab tutorial, I will try to show you the basics of Matlab user interface, data types, simple functions and mathematical operations. All with basic examples so that anyone with any level of programming knowledge can start using Matlab as a mathematical laboratory.

### Matlab User Interface

Start Matlab by a double click on the Matlab icon or else by searching for it under program. Now, there should be a large window containing several smaller. These could for instance be:

- Command Window
- Command History
- and Workspace.

This will of course depend on what version you are currently working in. This is the desktop of Matlab.

**Command Window:** Here you can write your own command lines and access your own files (m-files), but normally you can also see the output from the calculations in this window.

**Command History:** All command lines are saved here and can be seen in the window, but the same can be achieved by using the arrow button (up). The past command lines can the be seen in the command window.

**Workspace:** The variables that have been used or created during the execution will be shown in this window. Here you can see value, bytes and class. When you double click on the variables, the elements of the variables become visible.

These three windows should be the default when you start Matlab. Read more »

Tags: arrays in matlab, ceil, complex numbers, complex numbers in matlab, cos, floor, log10, logarithm, logN, m-files, mat-files, mathematical functions, mathlab, mathlab tutorial, mathlab tutorials, matlab, matlab beginner, matlab codes, matlab courses, matlab examples, matlab exercises, matlab function examples, matlab functions, matlab round function, matlab samples, matlab tutorial, matrices, matrices in matlab, matrix, operator priorities, plot legend, plot titles, plotting, plotting style matlab, round, sin, sqrt

Matlab Tutorials | admin, March 21, 2009 2:55 pm | Comments (0)