# List of Parameters¶

Below is a full list of the parameters that the `create_network`

function can take, along with a description of the values required.

## arrival_distributions¶

*Required*

Describes the inter-arrival distributions for each node and customer class. This is a dictionary, with keys as customer classes, and values are lists containing the inter-arrival distribution objects for each node. If only one class of customer is required it is sufficient to simply enter a list of inter-arrival distributions. For more details on inputting distributions, see How to Set Arrival & Service Distributions.

An example is shown:

```
arrival_distributions={'Class 0': [ciw.dists.Exponential(rate=2.4),
ciw.dists.Uniform(lower=0.3, upper=0.5)],
'Class 1': [ciw.dists.Exponential(rate=3.0),
ciw.dists.Deterministic(value=0.8)]}
```

An example where only one class of customer is required:

```
arrival_distributions=[ciw.dists.Exponential(rate=2.4),
ciw.dists.Exponential(rate=2.0)]
```

## batching_distributions¶

*Optional*

Describes the discrete distributions of size of the batch arrivals for each node and customer class. This is a dictionary, with keys as customer classes, and values are lists containing the batch distribution objects for each node. If only one class of customer is required it is sufficient to simply enter a list of batch distributions. For more details on batching, see How to Set Batch Arrivals.

An example is shown:

```
batching_distributions={'Class 0': [ciw.dists.Deterministic(value=1),
ciw.dists.Sequential(sequence=[1, 1, 2])],
'Class 1': [ciw.dists.Deterministic(value=3),
ciw.dists.Deterministic(value=2)]}
```

An example where only one class of customer is required:

```
batching_distributions=[ciw.dists.Deterministic(value=2),
ciw.dists.Deterministic(value=1)]
```

## baulking_functions¶

*Optional*

A dictionary of baulking functions for each customer class and each node. It describes the baulking mechanism of the customers. For more details see How to Simulate Baulking Customers. If left out, then no baulking occurs.

Example:

```
baulking_functions={'Class 0': [probability_of_baulking]}
```

## class_change_matrices¶

*Optional*

A dictionary of class change matrices for each node. For more details see How to Set Dynamic Customer Classes.

An example for a two node network with two classes of customer:

```
class_change_matrices=[
{'Class 0': {'Class 0': 0.3, 'Class 1': 0.4, 'Class 2': 0.3},
'Class 1': {'Class 0': 0.1, 'Class 1': 0.9, 'Class 2': 0.0},
'Class 2': {'Class 0': 0.5, 'Class 1': 0.1, 'Class 2': 0.4}},
{'Class 0': {'Class 0': 1.0, 'Class 1': 0.0, 'Class 2': 0.0},
'Class 1': {'Class 0': 0.4, 'Class 1': 0.5, 'Class 2': 0.1},
'Class 2': {'Class 0': 0.2, 'Class 1': 0.2, 'Class 2': 0.6}}
]
```

## number_of_servers¶

*Required*

A list of the number of parallel servers at each node.
If a server schedule is used, the schedule is given instead of a number.
For more details on server schedules, see How to Set Server Schedules.
A value of `float('inf')`

may be given is infinite servers are required.

Example:

```
number_of_servers=[1, 2, float('inf'), 1, [[1, 10], [2, 15]]]
```

## priority_classes¶

*Optional*

A dictionary mapping customer classes to priorities. For more information see How to Set Priority Classes. If left out, no priorities are used, that is all customers have equal priorities.

Example:

```
priority_classes={'Class 0': 0,
'CLass 1': 1,
'Class 2': 1}
```

## queue_capacities¶

*Optional*

A list of maximum queue capacities at each node.
If ommitted, default values of `float('inf')`

for every node are given.

Example:

```
queue_capacities=[5, float('inf'), float('inf'), 10]
```

## routing¶

*Required for more than 1 node*

*Optional for 1 node*

Describes how each customer class routes around the system. This may be a routing matrix for each customer class, or a list routing function for process-based simulations, see How to Define Process-Based Routing.

This is a dictionary, with keys as customer classes, and values are lists of lists (matrices) containing the routing probabilities. If only one class of customer is required it is sufficient to simply enter single routing matrix (a list of lists).

An example is shown:

```
routing={'Class 0': [[0.1, 0.3],
[0.0, 0.8]],
'Class 1': [[0.0, 1.0],
[0.0, 0.0]]}
```

An example where only one class of customer is required:

```
routing=[[0.5, 0.3],
[0.2, 0.6]]
```

If using only one node, the default value is:

```
routing={'Class 0': [[0.0]]}
```

Otherwise a process-based routing function:

```
routing=[routing_function]
```

## service_distributions¶

*Required*

Describes the service distributions for each node and customer class. This is a dictionary, with keys as customer classes, and values are lists containing the service distribution objects for each node. If only one class of customer is required it is sufficient to simply enter a list of service distributions. For more details on inputting distributions, see How to Set Arrival & Service Distributions.

An example is shown:

```
service_distributions={'Class 0': [ciw.dists.Exponential(rate=4.4),
ciw.dists.Uniform(lower=0.1, upper=0.9)],
'Class 1': [ciw.dists.Exponential(rate=6.0),
ciw.dists.Lognormal(mean=0.5, sd=0.6)]}
```

An example where only one class of customer is required:

```
service_distributions=[ciw.dists.Exponential(rate=4.8),
ciw.dists.Exponential(rate=5.2)]
```