Getting Started    

Functions

MATLAB provides a large number of standard elementary mathematical functions, including abs, sqrt, exp, and sin. Taking the square root or logarithm of a negative number is not an error; the appropriate complex result is produced automatically. MATLAB also provides many more advanced mathematical functions, including Bessel and gamma functions. Most of these functions accept complex arguments. For a list of the elementary mathematical functions, type

For a list of more advanced mathematical and matrix functions, type

Some of the functions, like sqrt and sin, are built-in. They are part of the MATLAB core so they are very efficient, but the computational details are not readily accessible. Other functions, like gamma and sinh, are implemented in M-files. You can see the code and even modify it if you want.

Several special functions provide values of useful constants.

pi
 3.14159265...
i
 Imaginary unit, -1
j
 Same as i
eps
 Floating-point relative precision, 2-52
realmin   
 Smallest floating-point number, 2-1022
realmax
 Largest floating-point number, (2-)21023
Inf
 Infinity
NaN
 Not-a-number

Infinity is generated by dividing a nonzero value by zero, or by evaluating well defined mathematical expressions that overflow, i.e., exceed realmax. Not-a-number is generated by trying to evaluate expressions like 0/0 or
Inf-Inf that do not have well defined mathematical values.

The function names are not reserved. It is possible to overwrite any of them with a new variable, such as

and then use that value in subsequent calculations. The original function can be restored with


 Operators Examples of Expressions