Introduction to Matlab

Common methods of mathematical modeling:Introduction to the differential equation--a general evaluation of statistical graphs and network interpolation and fitting data--numerical analysis and optimization method of regression analysis matlab Basic Representation method

1.MATLAB assignment Statement Two forms: variable = expression; An expression;

An expression is a formula that uses an operator to concatenate an operand, and the result is a matrix.
Attention:
(1) The second assignment is to assign the permanent variable ans.
(2) If you add a semicolon at the end of the statement, Matlab simply performs the assignment and no longer displays the result of the operation.
(3) In a statement, if the expression is too complex, a line can not be written, you may add three small black dots (...). ) as the endurance character.

2. Variable naming rules: Variable names are case sensitive. The first character of a variable must be an English letter and cannot exceed 31 characters. Variable names can contain characters, numbers, but not whitespace, punctuation.

3.MATLAB-expression

an arithmetic expression :
The key is /(right apart), (left), and for matrices, left and right divide represent two different divisor matrices and dividend matrix relationships.

Relational Expressions :
The key is not equal to ~=

Logical Expressions
& (with), | (or) and ~ (non) matrix representations

The basic unit of MATLAB's array preservation and transfer is not scalar , but array ; matlab arithmetic, relational, logical operation of the basic operational single source is not scalar, is an array.

Matrix type: one-dimensional, two-dimensional, multidimensional. Matrix Creation

Direct Input Method:
such as a = [1,2,3;4,5,6;7,8,9]. This is a matrix of 3 rows and 3 columns.

Colon expression method:
Colons can be used to produce vectors or to split matrices.
The General format is:
E1:e2:e3 where E1 is the initial value, E2 is the step, and E3 is the terminating value. That is, a colon expression can produce a line vector that starts from E1 to E3 and ends with a step e2.

Using the function linspace:
The general format is x = Linspace (x1, x2, N)
The function generates a row vector of n elements, X1 to its first element, X2 to its last element, and the interval between elements between X1,X2 (X2-X1)/(n-1).

Creation of column vectors
1. Using the square brackets "[]" operator, use the semicolon ":" to split the line.
2. Create the line vector first and then transpose.

Creation of Two-dimensional arrays
1. Using the "[]" operator
2. Function Method:
The function ones (generates all 1 matrices),zeros (generates all 0 matrices).

A two-dimensional array is arranged in columns from top to bottom , requiring the total number of array elements to be the same. the addressing and searching of array elements

1. Addressing the array element
"Full subscript" identification: Each dimension corresponds to a subscript.
such as a (2,3) represents the element of the "2nd row 3rd column" of the two-dimensional array A. For a one-dimensional array, you can use a subscript.

"Single subscript" Identification: Use a subscript to indicate the position of the element in the array.
For a two-dimensional array, it is envisaged that all the columns of the two-dimensional array, in order of the first and last phase into a "one-dimensional array." string

a sequence of characters enclosed in a single apostrophe is called a string. MATLAB treats a string as a line vector, with each element corresponding to one character. MATLAB Operations Note:

1./(right except), \ (left except) the difference:
The operation of a\b and b/a can be realized by setting A non-singular matrix.
a\b corresponds to the inverse left multiplier b,inv (a) *b of A;
b/a corresponds to the inverse right multiplication of a b,b*inv (a);
While the scalar left and right divide, the two are the same.

2. Point arithmetic:. * (Point multiplication)./(point right). \ (point left)
Two matrices If a point operation is performed, the corresponding element in the matrix is associated with the operation.