[ ]
| Brackets are used to form vectors and matrices. [6.9 9.64 sqrt(-1)]
is a vector with three elements separated by blanks. [6.9, 9.64, i]
is the same thing. [1+j 2-j 3] and [1 +j 2 -j 3] are not the same.
The first has three elements, the second has five.
[11 12 13; 21 22 23] is a 2-by-3 matrix. The semicolon ends the first
row.
Vectors and matrices can be used inside [ ] brackets. [A B;C] is
allowed if the number of rows of A equals the number of rows of B and
the number of columns of A plus the number of columns of B equals the
number of columns of C. This rule generalizes in a hopefully obvious
way to allow fairly complicated constructions.
A = [ ] stores an empty matrix in A. A(m,:) = [ ] deletes row m of A.
A(:,n) = [ ] deletes column n of A. A(n) = [ ] reshapes A into a
column vector and deletes the third element.
[A1,A2,A3...] = function assigns function output to multiple
variables.
For the use of [ and ] on the left of an "=" in multiple assignment
statements, see lu, eig, svd, and so on.
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{ }
| Curly braces are used in cell array assignment statements. For
example.,
A(2,1) = {[1 2 3; 4 5 6]}, or A{2,2} = ('str'). See help paren
for more information about { }.
|
( )
| Parentheses are used to indicate precedence in arithmetic expressions
in the usual way. They are used to enclose arguments of functions in
the usual way. They are also used to enclose subscripts of vectors and
matrices in a manner somewhat more general than usual. If X and V
are vectors, then X(V) is [X(V(1)), X(V(2)), ..., X(V(n))]. The
components of V must be integers to be used as subscripts. An error
occurs if any such subscript is less than 1 or greater than the size of X.
Some examples are
See help paren for more information about ( ).
|
| If X has n components, X(n:-1:1) reverses them. The same indirect
subscripting works in matrices. If V has m components and W has n
components, then A(V,W) is the m-by-n matrix formed from the
elements of A whose subscripts are the elements of V and W. For
example, A([1,5],:) = A([5,1],:) interchanges rows 1 and 5 of A.
|
=
| Used in assignment statements. B = A stores the elements of A in B.
== is the relational equals operator. See the Relational Operators
page.
|
'
| Matrix transpose. X' is the complex conjugate transpose of X. X.' is the nonconjugate transpose.
Quotation mark. 'any text' is a vector whose components are the
ASCII codes for the characters. A quotation mark within the text is
indicated by two quotation marks.
|
.
| Decimal point. 314/100, 3.14 and .314e1 are all the same.
Element-by-element operations. These are obtained using .* , .^ , ./,
or .\. See the Arithmetic Operators page.
|
.
| Field access. A.(field) and A(i).field, when A is a structure, access
the contents of field.
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..
| Parent directory. See cd.
|
...
| Continuation. Three or more points at the end of a line indicate
continuation.
|
,
| Comma. Used to separate matrix subscripts and function arguments.
Used to separate statements in multistatement lines. For
multi-statement lines, the comma can be replaced by a semicolon to
suppress printing.
|
;
| Semicolon. Used inside brackets to end rows. Used after an expression
or statement to suppress printing or to separate statements.
|
%
| Percent. The percent symbol denotes a comment; it indicates a logical
end of line. Any following text is ignored. MATLAB displays the first
contiguous comment lines in a M-file in response to a help command.
|
!
| Exclamation point. Indicates that the rest of the input line is issued
as a command to the operating system.
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