Geoscience Reference
In-Depth Information
organized in directories on the hard disk. h e default search path includes
only the
MATLAB_R2014b
directory that has been created by the installer
in the applications folder and the default working directory
MATLAB
. To
see which directories are in the search path or to add new directories, select
Set Path
from the
Home
toolstrip of the MATLAB desktop, and use the
Set
Path
dialog box. h e modii ed search path is saved in a i le
pathdef.m
on your
hard disk. h e sot ware will then in future read the contents of this i le and
direct MATLAB to use your custom path list.
2.3 The Syntax
h e name MATLAB stands for
matrix laboratory
. h e classic object handled
by MATLAB is a
matrix
, i.e., a rectangular two-dimensional
array
of numbers.
A simple 1-by-1 array is a
scalar
. Arrays with one column or row are
vectors
,
time series or other one-dimensional data i elds. An
m
-by-
n
array can be
used for a digital elevation model or a grayscale image. Red, green and blue
(RGB) color images are usually stored as three-dimensional arrays, i.e., the
colors red, green and blue are represented by an
m
-by-
n
-by-3 array.
Before proceeding, we need to clear the workspace by typing
clear
at er the prompt in the Command Window. Clearing the workspace is
always recommended before working on a new MATLAB project to avoid
name conl icts with previous projects. We can also go a step further, close
all Figure Windows using
close all
and clear the content of the Command
Window using
clc
. It is therefore recommended that a new MATLAB project
should always start with the line
clear, close all, clc
Entering matrices or arrays in MATLAB is easy. To enter an arbitrary matrix,
type
A = [2 4 3 7; 9 3 -1 2; 1 9 3 7; 6 6 3 -2]
which i rst dei nes a variable
A
, then lists the elements of the array in square
brackets. h e rows of
A
are separated by semicolons, whereas the elements
of a row are separated by blank spaces, or alternatively, by commas. At er
pressing
return
, MATLAB displays the array
A =
2 4 3 7
9 3 -1 2
