# Math FAQ

A space for Commons-Math frequently asked questions.

### 0. How can I get involved in commons-math?

Follow the directions under "contributing" in the Commons Math Developers Guide]. Feedback and contributions from all interested parties are welcome. Extensive Java or mathematical knowledge is not required to participate (though some knowledge of one or the other is certainly helpful

### 1. Are instances of org.apache.commons.math.stat.descriptive.DescriptiveStatisticsImpl thread-safe?

No, they are not. Version 2.0 includes synchronized versions of several classes, including a SynchronizedDescriptiveStatistics class.

### 2. Can code derived from "Numerical Recipes" routines be included in commons-math?

Algorithms implemented in "Numerical Recipes" are licensed under terms that are incompatible with the Apache license. As such, commons-math can not contain any code derived from these routines. The precedent we have established is to not allow any code developed using NR as a source and instead find alternate citations for the algorithms detailed in NR.