Reference 〉 Function

Helipad.spatial(dimint|tuple10, wrapbool|tupleTrue, cornersbool|floatFalse, geometrystr|class'rect', offmapboolFalse)

Sets up functions, properties, and methods for spatial models. This function should be run before the control panel is drawn.

The function does several things:

  1. Creates a spatially fixed patch primitive to represent map coordinates.
  2. Creates a network named 'space' connecting each patch to its neighbors.
  3. Initializes the model.patches property.
  4. Adds movement methods and properties to agents of all primitives except patches, which cannot move.
    • agent.moveUp(), agent.moveDown(), agent.moveLeft(), and agent.moveRight() — move the agent one patch over starting from the current location.
    • agent.move(x, y) — moves the agent some number of patches over and some number of patches down.
    • agent.moveTo(x, y) or agent.moveTo(patch) — moves the agent to the patch located at (x,y) or the location of the patch.
    • agent.distanceFrom(agent) — calculates the spatial distance between the current agent and another.
    • agent.position — the current coordinates of the agent. Patches also have patch.position, but it cannot be modified. Integer locations correspond to the center of a patch, so the range of the x dimension is -0.5 to dim[0]-0.5, and mutatis mutandis for y.
    • agent.orientTo(agent) — Sets the agent’s orientation toward a particular patch or another agent.
    • agent.forward(steps) — Moves the agent some distance in the direction of its current orientation.
    • agent.patch — The patch that the agent is currently on.
  5. Registers the Charts visualizer and a network plot with a spatial layout upon it. The plot object has a config() method that allows various aspects of the map to be customized. By default patches are displayed in a grid with colors corresponding to a specified parameter, and agents are displayed as dots of their breed color. The model.visual object can be used to display other chart plots alongside the spatial map. Note that functions calling model.spatial() do not then need to call model.useVisual().

By default, agents are randomly positioned on the grid on model launch. The agentPosition hook can be used to override this and specify agents’ initial positions.

Parameters

  • dim — int|tuple, optional

    The map dimensions. Pass an integer for a square map, or a two-element tuple to specify (x,y) dimensions.

    Default value: 10

  • wrap — bool|tuple, optional

    Whether patches at the edges of the map should be connected to patches on the opposite edge, if the geometry is tesselable. PatchesRect, for example, can support several geometries:

    • False: Rectangular (no wrapping).
    • True: Toroidal (wrapping on both axes).
    • (True, False) or (False, True): Cylindrical (wrapping on one axis).

    Default value: True

  • corners — bool|float, optional

    Whether to connect patches to their corners, and if so, the weight of the connection (between 0 and 1). If True, Patch.neighbors will return the Moore neighborhood; otherwise the Von Neumann neighborhood.

    Default value: False

  • geometry — str|class, optional

    The coordinate system to be used. Currently supports 'rect', 'polar', and 'geo'. Can also take a class specifying a custom coordinate system.

    Default value: 'rect'

  • offmap — bool, optional

    Whether agents can enter areas of the map with no patch. If False and an agent tries to move() to a coordinate with no patch, the move will fail and a warning will be raised.

    Default value: False

Return Value — AgentsPlot

The AgentsPlot object, subclass of ChartPlot, which can be used to customize various aspects of the map visualization. See especially the options in AgentsPlot.config().

Notes and Examples

  1. charwick

    Jan 10, 2023 at 2:03

    As of Helipad 1.5, the grid dimensions are no longer stored as global parameters, but as properties of the patchgrid object. They are thus no longer settable in the control panel by default. A grid dimension parameter can, however, be added with a callback to update the patchgrid object:

    maxdim = 30
mapPlot = heli.spatial(dim=maxdim)

def setdim(model, var, val): model.patches.dim = (int(val), int(val))
heli.params.add('dim', 'Dimension', 'slider', maxdim, opts={'low': 4, 'high': maxdim, 'step': 1}, runtime=False, callback=setdim)

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