| 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. Built-in functions 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.
There are some differences between built-in functions and other functions. For example, for built-in functions, you cannot see the code. For other functions, 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, |
realmin |
Smallest floating-point number, |
realmax |
Largest floating-point number, |
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 | |
© 1994-2005 The MathWorks, Inc.
