| 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, |
j |
Same as |
eps |
Floating-point relative precision, 2-52 |
realmin |
Smallest floating-point number, 2-1022 |
realmax |
Largest floating-point number, (2- |
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 | |
-1
)21023