This guide is intended to help programmers quickly find what they need to develop solutions using Commons Math. It also provides a supplement to the javadoc API documentation, providing a little more explanation of the mathematical objects and functions included in the package.
Commons Math is made up of a small set of math/stat utilities addressing programming problems like the ones in the list below. This list is not exhaustive, it's just meant to give a feel for the kinds of things that Commons Math provides.
We are actively seeking ideas for additional components that fit into the Commons Math vision of a set of lightweight, self-contained math/stat components useful for solving common programming problems. Suggestions for new components or enhancements to existing functionality are always welcome! All feedback/suggestions for improvement should be sent to the commons-dev mailing list with [math] at the beginning of the subject line.
Commons Math is divided into sixteen subpackages, based on functionality provided.
You should always read the javadoc class and method comments carefully when using Commons Math components in your programs. The javadoc provides references to the algorithms that are used, usage notes about limitations, performance, etc. as well as interface contracts. Interface contracts are specified in terms of preconditions (what has to be true in order for the method to return valid results), special values returned (e.g. Double.NaN) or exceptions that may be thrown if the preconditions are not met, and definitions for returned values/objects or state changes.
When the actual parameters provided to a method or the internal state of an object make a computation meaningless, a MathIllegalArgumentException or MathIllegalStateException may be thrown. Exact conditions under which runtime exceptions (and any other exceptions) are thrown are specified in the javadoc method comments. In some cases, to be consistent with the IEEE 754 standard for floating point arithmetic and with java.lang.Math, Commons Math methods return Double.NaN values. Conditions under which Double.NaN or other special values are returned are fully specified in the javadoc method comments.
As of version 2.2, the policy for dealing with null references is as follows: When an argument is unexpectedly null, a NullArgumentException is raised to signal the illegal argument. Note that this class does not inherit from the standard NullPointerException but is a subclass of MathIllegalArgumentException.
This product includes software developed by other third parties and distributed under licenses terms compatible with Apache License, Version 2.0. All the licenses of such third parties products are available in the distribution in the LICENSE.txt file. Some products require additional attribution, these attributions can be found in the NOTICE.txt file. These files are available both in the source packages and in the binaries distribution jar files.