Reference for `DiscreteFieldGrapher`

This utility uses matplotlib to graph vehicles in descrete positions as defined by an instance of FieldDiscretizer

WARNING: This class is EXTREMELY ineffecient and should not be used in a loop which timing is important. Its primary use is for debuging.

You can see a example of how to use this visualizer with the FieldDiscretizer here.

Source code in mivp_agent/aquaticus/field.py

class DiscreteFieldGrapher:
  '''
  This utility uses matplotlib to graph vehicles in descrete positions as defined by an instance of [`FieldDiscretizer`][mivp_agent.aquaticus.field.FieldDiscretizer]

  **WARNING:** This class is *EXTREMELY* ineffecient and should not be used in a loop which timing is important. Its primary use is for debuging.

  You can see a example of how to use this visualizer with the FieldDiscretizer [here](https://github.com/mivp-agent/moos-ivp-agent/blob/main/examples/DiscreteField/run.py).
  '''
  def __init__(self, discretizer):
    '''
    Args:
      discretizer (FieldDiscretizer): Used to plot discrete points and during vehicle initalization.
    '''
    assert isinstance(discretizer, FieldDiscretizer), 'discretizer is of wrong type'

    # Store discretizer
    self._discretizer = discretizer

    # Construct field plot
    plt.ion()
    self._field_fig, self._field_ax = construct_field_figure()

    # Add grid points to field graph
    for p in self._discretizer._point_idx_map:
      # Ignore the entry used for out of field points
      if p is None:
        continue

      self._field_ax.plot([p[0]], [p[1]], marker='.', markersize=3, color='dimgray')

    # Draw for first time
    self._field_fig.canvas.draw()

    # Create data structure for storing vehicle's locations
    self._vehicles = {}

  def init_vehicle(self, name, color, start_pos=FIELD_OUT_BOUNDS_POINT, plot=True):
    '''
    Initalizes a vehicle specified by `name` in the DiscreteFieldGrapher class and it's matplotlib plot. To update the vehicles initalized by this method see 
    [`update_vehicle()`][mivp_agent.aquaticus.field.DiscreteFieldGrapher.update_vehicle].

    Args:
      name (str): The name (or key) to list the vehicle under.
      color (str): A matplotlib [named color](https://matplotlib.org/stable/gallery/color/named_colors.html).
      start_pos (tuple): A tuple where containing the x / y position to initally render the vehicle.
      plot (bool): A boolean indicating if the the plot should be redrawn after vehicle initalization.
    Raises:
      RuntimeError: If the specified `name` has already been initalized.
    '''
    if name in self._vehicles:
      raise RuntimeError(f'FieldGrapher alread has vehicle named "{name}"')

    if start_pos != FIELD_OUT_BOUNDS_POINT:
      start_pos = self._discretizer.to_discrete_point(
        start_pos[0],
        start_pos[1]
      )

    self._vehicles[name] = {
      'circle': plt.Circle(start_pos, 2, color=color),
      'label': self._field_ax.text(start_pos[0] + 3, start_pos[1]+3, name),
      'position': start_pos
    }

    self._field_ax.add_artist(self._vehicles[name]['circle'])

    if plot:
      self._plot()


  def update_vehicle(self, name, discrete_position, plot=True):
    '''
    Used to update the position of a vehicle which has been previously initalized via [`init_vehicle()`][mivp_agent.aquaticus.field.DiscreteFieldGrapher.init_vehicle]

    Args:
      name (str): The name (or key) to list the vehicle under.
      discrete_position (tuple): A tuple where containing the **DISCRETE** x / y position to render the vehicle at. This method **will not** pass the point through the discretizer.
      plot (bool): A boolean indicating if the the plot should be redrawn after vehicle update.

    Raises:
      RuntimeError: If the specified `name` has not been initalized previously.
    '''
    if name not in self._vehicles:
      raise RuntimeError(f'FieldGrapher cannot find vehicle with name "{name}"')

    if discrete_position is None:
      discrete_position = FIELD_OUT_BOUNDS_POINT

    # Remove old label position
    self._vehicles[name]['label'].set_visible(False)

    # Update graphic
    self._vehicles[name]['circle'].center = discrete_position
    self._vehicles[name]['label'] = self._field_ax.text(discrete_position[0]+3, discrete_position[1]+3, name)
    self._vehicles[name]['position'] = discrete_position

    if plot:
      self._plot()

  def _plot(self):
    # Draw the vehicles
    for v in self._vehicles:
      self._field_ax.draw_artist(self._vehicles[v]['circle'])

    self._field_fig.canvas.flush_events()

`init(self, discretizer)` `special`

Parameters:

Name	Type	Description	Default
`discretizer`	`FieldDiscretizer`	Used to plot discrete points and during vehicle initalization.	required

Source code in mivp_agent/aquaticus/field.py

def __init__(self, discretizer):
  '''
  Args:
    discretizer (FieldDiscretizer): Used to plot discrete points and during vehicle initalization.
  '''
  assert isinstance(discretizer, FieldDiscretizer), 'discretizer is of wrong type'

  # Store discretizer
  self._discretizer = discretizer

  # Construct field plot
  plt.ion()
  self._field_fig, self._field_ax = construct_field_figure()

  # Add grid points to field graph
  for p in self._discretizer._point_idx_map:
    # Ignore the entry used for out of field points
    if p is None:
      continue

    self._field_ax.plot([p[0]], [p[1]], marker='.', markersize=3, color='dimgray')

  # Draw for first time
  self._field_fig.canvas.draw()

  # Create data structure for storing vehicle's locations
  self._vehicles = {}

`init_vehicle(self, name, color, start_pos=(30, 10), plot=True)`

Initalizes a vehicle specified by name in the DiscreteFieldGrapher class and it's matplotlib plot. To update the vehicles initalized by this method see update_vehicle().

Parameters:

Name	Type	Description	Default
`name`	`str`	The name (or key) to list the vehicle under.	required
`color`	`str`	A matplotlib named color.	required
`start_pos`	`tuple`	A tuple where containing the x / y position to initally render the vehicle.	`(30, 10)`
`plot`	`bool`	A boolean indicating if the the plot should be redrawn after vehicle initalization.	`True`

Exceptions:

Type	Description
`RuntimeError`	If the specified `name` has already been initalized.

Source code in mivp_agent/aquaticus/field.py

def init_vehicle(self, name, color, start_pos=FIELD_OUT_BOUNDS_POINT, plot=True):
  '''
  Initalizes a vehicle specified by `name` in the DiscreteFieldGrapher class and it's matplotlib plot. To update the vehicles initalized by this method see 
  [`update_vehicle()`][mivp_agent.aquaticus.field.DiscreteFieldGrapher.update_vehicle].

  Args:
    name (str): The name (or key) to list the vehicle under.
    color (str): A matplotlib [named color](https://matplotlib.org/stable/gallery/color/named_colors.html).
    start_pos (tuple): A tuple where containing the x / y position to initally render the vehicle.
    plot (bool): A boolean indicating if the the plot should be redrawn after vehicle initalization.
  Raises:
    RuntimeError: If the specified `name` has already been initalized.
  '''
  if name in self._vehicles:
    raise RuntimeError(f'FieldGrapher alread has vehicle named "{name}"')

  if start_pos != FIELD_OUT_BOUNDS_POINT:
    start_pos = self._discretizer.to_discrete_point(
      start_pos[0],
      start_pos[1]
    )

  self._vehicles[name] = {
    'circle': plt.Circle(start_pos, 2, color=color),
    'label': self._field_ax.text(start_pos[0] + 3, start_pos[1]+3, name),
    'position': start_pos
  }

  self._field_ax.add_artist(self._vehicles[name]['circle'])

  if plot:
    self._plot()

`update_vehicle(self, name, discrete_position, plot=True)`

Used to update the position of a vehicle which has been previously initalized via init_vehicle()

Parameters:

Name	Type	Description	Default
`name`	`str`	The name (or key) to list the vehicle under.	required
`discrete_position`	`tuple`	A tuple where containing the DISCRETE x / y position to render the vehicle at. This method will not pass the point through the discretizer.	required
`plot`	`bool`	A boolean indicating if the the plot should be redrawn after vehicle update.	`True`

Exceptions:

Type	Description
`RuntimeError`	If the specified `name` has not been initalized previously.

Source code in mivp_agent/aquaticus/field.py

def update_vehicle(self, name, discrete_position, plot=True):
  '''
  Used to update the position of a vehicle which has been previously initalized via [`init_vehicle()`][mivp_agent.aquaticus.field.DiscreteFieldGrapher.init_vehicle]

  Args:
    name (str): The name (or key) to list the vehicle under.
    discrete_position (tuple): A tuple where containing the **DISCRETE** x / y position to render the vehicle at. This method **will not** pass the point through the discretizer.
    plot (bool): A boolean indicating if the the plot should be redrawn after vehicle update.

  Raises:
    RuntimeError: If the specified `name` has not been initalized previously.
  '''
  if name not in self._vehicles:
    raise RuntimeError(f'FieldGrapher cannot find vehicle with name "{name}"')

  if discrete_position is None:
    discrete_position = FIELD_OUT_BOUNDS_POINT

  # Remove old label position
  self._vehicles[name]['label'].set_visible(False)

  # Update graphic
  self._vehicles[name]['circle'].center = discrete_position
  self._vehicles[name]['label'] = self._field_ax.text(discrete_position[0]+3, discrete_position[1]+3, name)
  self._vehicles[name]['position'] = discrete_position

  if plot:
    self._plot()

Reference for DiscreteFieldGrapher

__init__(self, discretizer) special

init_vehicle(self, name, color, start_pos=(30, 10), plot=True)

update_vehicle(self, name, discrete_position, plot=True)

Reference for `DiscreteFieldGrapher`

`init(self, discretizer)` `special`

`init_vehicle(self, name, color, start_pos=(30, 10), plot=True)`

`update_vehicle(self, name, discrete_position, plot=True)`