# MATLAB

Names of variables and functions can contain any characters except the special, but they must begin with a letter. Use a separator, when writing several operators in the same line. Comma serves as delimiter. Delimiter can be omitted after the single or the last operator in a string.

** Operators have two forms of recording:**

- the implicit assignment (expression);
- with explicit assignment (variable = expression).

When you use the implicit assignment, the system automatically creates a variable called "ans", and assigns it a value of the result.

Command-line buffer length is limited by 256 characters. If you need to move the operator to the next line, you must enter a line continuation character ... (three points), press Enter key to continue the operator. The system uses two types of MATLAB arithmetic operations: on arrays and on matrices; operations on arrays are performed element by element, and on matrices - in accordance with the rules of linear algebra.

The numbers in MATLAB can be represented with a fixed and floating point, be positive or negative, fractional, real and complex.

** Features of numbers presentation in MATLAB: **

- imaginary unit is represented by two characters "i" and "j";
- integral and fractional parts are separated by point;
- order of the number is separated from mantissa by character "e".

In the process of tasks solving, variables can take up a lot of computer memory. Function "clear" is used in** ** MATLAB to clear the memory from the variables. This function has has such syntax:

- clear х — elimination of "х" variable;
- clear — elimination of all variables;
- clear а b с — elimination of the family of variables.

**Constant** — is the numerical value of a unique name, which has a mathematical meaning. In MATLAB are often used following constants:

- inf — machine infinity;
- arts — name of the variable, which stores the result of the calculation;
- pi — «number Pi»;
- eps — error in operations with numbers with floating point;
- realmin — minimal number with floating point;
- reaimax — maximal number with floating point;
- NaN — non-numeric character data (Not a Number).

** **

**Mathematical functions** are represented as fun (x),

where fun — function name,

х — argument as a: number, vector or matrix.

Numbers, elements, vectors or matrix can be real or complex.

**For graphing are used special functions.**

When you set the style, parameter "s" (vector of constants) is represented as a vector or strings of characters. To set the title of graph, axis labels and grid lines are used such functions: title, xlabel, уlabel, grid on.