pynumutil

Simple Numerical Utilities. In particular some objects for comparing and calculating difference between complex numbers.

Installation

Clone the repository and install with the following commands:

git clone https://github.com/petersbingham/pynumutil.git
cd pynumutil
python setup.py install

Dependencies

None

Usage

Reader is referred to the pynumutil/__init__.py file for details. There are two comparison classes NearlyEqual and RationalCompare1. More are planned for later.

nearlyEqual

NearlyEqual returns a boolean from it's functions (see __init__.py file) if two numbers are deemed to be nearly equal to one another. If the numbers are complex then the test is performed separately on the real and imaginary components. The type of test is determined by the number of and values of the parameters supplied to the constructor, according to the following:

• 0 parameters: The test is an absolute comparison and tests positive if the absolute of the difference is less than or equal to 10^-8.
• 1 parameter: This specifies the threshold for comparison (ie replaces the 10^-8). The test type is absolute.
• 2 parameters: The first parameter specifies the test type, the second the threshold for comparison. The test type can be specified using the enum in the package scope, either absolute or percent.
• 4 parameters: As for 2 parameters except applied separately to both the real and imaginary components separately.

RationalCompare1

This applies the formula |x-y| / max(|x|,|y|) separately to the real and imaginary components of two complex numbers x and y if both |x| and |y| are greater than some minimum value (ztol). If either |x| or |y| exclusively are less than or equal to ztol then the formula is applied using the minimum value for the smallest of |x| and |y|. If both |x| and |y| are less than or equal to ztol then zero is returned. ztol is optionally specified in the constructor of RationalCompare1, along with rtol, which specifies a value equal to or above which the numbers are deemed distinct.

match_closest

For a container of shots matches each to the closest target from a container of targets. A condition is that a single shot can only be associated with a single target. Returns a list of two element lists; first element the target, second the closest shot.