# Utilities¶

## Decorators¶

Decorators allow for input checking and default parameter setting for algorithms.

 binary_quadratic_model_sampler(which_args) Decorator to validate sampler arguments.

## Graph Indexing¶

See Coordinates Conversion on instantiating the needed lattice size and setting correct domain and range for coordinates in a QPU working graph.

For the iterator versions of these functions, see the code.

### Chimera¶

 Convert a 4-term Chimera coordinate to a linear index. Convert a linear index to a 4-term Chimera coordinate. Attempts to determine the Chimera indices of the nodes in graph G.

### Pegasus¶

 Convert a linear index into a 5-term nice coordinate. Convert a linear index into a 4-term Pegasus coordinate. Convert a 5-term nice coordinate into a linear index. Convert a 5-term nice coordinate into a 4-term Pegasus coordinate. Convert a 4-term Pegasus coordinate into a linear index. Convert a 4-term Pegasus coordinate to a 5-term nice coordinate.

## Exceptions¶

Base exceptions and errors for D-Wave NetworkX.

All exceptions are derived from NetworkXException.

 DWaveNetworkXException Base class for exceptions in DWaveNetworkX. DWaveNetworkXMissingSampler Exception raised by an algorithm requiring a discrete model sampler when none is provided.