Graphics Programs Reference
In-Depth Information
To change the vector X from a row vector to a column vector, put a prime ( ' )
after X :
>> X'
ans =
0
2
4
6
8
10
Youcanperformmathematicaloperationsonvectors.Forexample,tosquare
the elements of the vector X , type
>> X.ˆ2
ans =
0
4
16
36
64
100
The period in this expression is very important; it says that the numbers
in X should be squared individually, or element-by-element . Typing Xˆ2 would
tell MATLAB to use matrix multiplication to multiply X by itself and would
produce an error message in this case. (We discuss matrices below and in
Chapter 4.) Similarly, you must type .* or ./ if you want to multiply or di-
vide vectors element-by-element. For example, to multiply the elements of the
vector X by the corresponding elements of the vector Y , type
>> X.*Y
ans =
0
-6
20
-12
64
10
Most MATLAB operations are, by default, performed element-by-element.
For example, you do not type a period for addition and subtraction, and you
can type exp(X) to get the exponential of each number in X (the matrix ex-
ponential function is expm ). One of the strengths of MATLAB is its ability to
efficiently perform operations on vectors.
Search WWH ::




Custom Search