# Package sim2net.speed¶

This package provides a collection of speed distribution classes.

Speed is a scalar quantity that describes the rate of change of a node position in a simulation area (see: sim2net.area).

Note

In all speed distribution classes the quantity of speed should be considered as simulation area units per one simulation time unit (see: sim2net._time).

For example, the value of speed equal to $$5$$ would mean five units of simulation area per one unit of simulation time.

## Module sim2net.speed._speed¶

Contains an abstract class that should be implemented by all speed distribution classes.

class sim2net.speed._speed.Speed(name)

Bases: object

This class is an abstract class that should be implemented by all speed distribution classes.

Parameters:
• name (str): a name of the implemented speed distribution.
current

(Property) A value of the current speed of type float.

Raises:
• NotImplementedError: this property is an abstract property.
get_new()

Assigns a new speed value.

Returns:
(float) a new speed value.
Raises:
• NotImplementedError: this method is an abstract method.
logger

(Property) A logger object of the logging.Logger class with an appropriate channel name.

random_generator

(Property) An object representing the sim2net.utility.randomness._Randomness pseudo-random number generator.

## Module sim2net.speed.constant¶

Provides an implementation of a constant node speed. In this case a speed of a node is constant at a given value.

class sim2net.speed.constant.Constant(speed)

This class implements a constant node speed fixed at a given value.

Parameters:
• speed (float): a value of the node speed.

Example:

>>> speed = Constant(5.0)
>>> speed.current
5.0
>>> speed.get_new()
5.0
>>> speed = Constant(-5.0)
>>> speed.current
5.0
>>> speed.get_new()
5.0

current

(Property) The absolute value of the current speed of type float.

get_new()

Returns the absolute value of the given node speed of type float.

## Module sim2net.speed.normal¶

Provides an implementation of the normal speed distribution. In this case a speed of a node is assigned at random with the normal, i.e. Gaussian, probability distribution.

class sim2net.speed.normal.Normal(mean=0.0, standard_deviation=0.2)

This class implements the normal speed distribution that assigns node’s speeds with the Gaussian probability distribution.

(Defaults to standard normal distribution.)

Parameters:
• mean (float): a value of the expectation (default: 0.0);
• standard_deviation (float): a value of the standard deviation (default: 0.2).
current

(Property) A value of the current speed of type float (or None if the value has yet not been assigned).

get_new()

Assigns a new speed value.

Warning

Depending on distribution parameters, negative values may be randomly selected.

Returns:
(float) the absolute value of a new speed.
mean

(Property) A value of the expectation of type float.

## Module sim2net.speed.uniform¶

Provides an implementation of the uniform speed distribution. In this case a speed of a node is assigned at random with the uniform probability distribution.

class sim2net.speed.uniform.Uniform(minimal_speed, maximal_speed)

This class implements the uniform speed distribution that assigns node’s speeds from a given range with equal probability.

Parameters:
• minimal_speed (float): a value of a node’s minimal speed;
• maximal_speed (float): a value of a node’s maximal speed.
current

(Property) A value of the current speed of type float (or None if the value has yet not been assigned).

get_new()

Assigns a new speed value.

Warning

Depending on distribution parameters, negative values may be randomly selected.

Returns:
(float) the absolute value of a new speed.