<< Chapter < Page Chapter >> Page >
This module covers basic complex and matrix operations in an m-file environment.

Complex numbers

m-file environments have excellent support for complex numbers. The imaginaryunit is denoted by i or (as preferred in Electrical Engineering) j . To create complex variables z 1 7 and z 2 2 e simply enter z1 = 7 + j and z2 = 2*exp(j*pi)

The table gives an overview of the basic functions for manipulating complex numbers, where z is a complex number.

Manipulating complex numbers
m-file
Re( z ) real(z)
Im( z ) imag(z)
z abs(z)
Angle( z ) angle(z)
z * conj(z)

Operations on matrices

In addition to scalars, m-file environments can operate on matrices. Some common matrix operations are shown in the Table below; in this table, M and N are matrices.

Common matrix operations
Operation m-file
M N M*N
M -1 inv(M)
M T M'
det( M ) det(M)

Some useful facts:

  • The functions length and size are used to find the dimensions of vectors and matrices, respectively.
  • Operations can also be performed on each element of a vector or matrix by proceeding the operator by ".", e.g .* , .^ and ./ .

Let A 1 1 1 1 . Then A^2 will return AA 2 2 2 2 , while A.^2 will return 1 2 1 2 1 2 1 2 1 1 1 1 .

Got questions? Get instant answers now!

Given a vector x, compute a vector y having elements y n 1 x n . This can be easily be done the command y=1./sin(x) Note that using / in place of ./ would result in the (common) error " Matrix dimensions must agree ".

Got questions? Get instant answers now!

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Freshman engineering problem solving with matlab. OpenStax CNX. Apr 23, 2007 Download for free at http://cnx.org/content/col10325/1.18
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Freshman engineering problem solving with matlab' conversation and receive update notifications?

Ask