# pyswarms.utils.decorators package¶

The pyswarms.decorators module implements a decorator that can be used to simplify the task of writing the cost function for an optimization run. The decorator can be directly called by using @pyswarms.cost.

pyswarms.utils.decorators.cost(cost_func)[source]

A decorator for the cost function

This decorator allows the creation of much simpler cost functions. Instead of writing a cost function that returns a shape of (n_particles, 0) it enables the usage of shorter and simpler cost functions that directly return the cost. A simple example might be:

The decorator expects your cost function to use a d-dimensional array (where d is the number of dimensions for the optimization) as and argument.

Note

Some numpy functions return a np.ndarray with single values in it. Be aware of the fact that without unpacking the value the optimizer will raise an exception.

Parameters: cost_func (callable) – A callable object that can be used as cost function in the optimization (must return a float or an int). The vectorized output for all particles as defined by cost_func callable