Source code for mesa.visualization.TextVisualization

Text Visualization

Base classes for ASCII-only visualizations of a model.
These are useful for quick debugging, and can readily be rendered in an IPython
Notebook or via text alone in a browser window.


TextVisualization: Class meant to wrap around a Model object and render it
in some way using Elements, which are stored in a list and rendered in that
order. Each element, in turn, renders a particular piece of information as

ASCIIElement: Parent class for all other ASCII elements. render() returns its
representative string, which can be printed via the overloaded __str__ method.

TextData: Uses getattr to get the value of a particular property of a model
and prints it, along with its name.

TextGrid: Prints a grid, assuming that the value of each cell maps to exactly
one ASCII character via a converter method. This (as opposed to a dictionary)
is used so as to allow the method to access Agent internals, as well as to
potentially render a cell based on several values (e.g. an Agent grid and a
Patch value grid).
# Pylint instructions: allow single-character variable names.
# pylint: disable=invalid-name

[docs]class TextVisualization: """ASCII-Only visualization of a model. Properties: model: The underlying model object to be visualized. elements: List of visualization elements, which will be rendered in the order they are added. """ def __init__(self, model): """Create a new Text Visualization object.""" self.model = model self.elements = []
[docs] def render(self): """Render all the text elements, in order.""" for element in self.elements: print(element)
[docs] def step(self): """Advance the model by a step and print the results.""" self.model.step() self.render()
[docs]class ASCIIElement: """Base class for all TextElements to render. Methods: render: 'Renders' some data into ASCII and returns. __str__: Displays render() by default. """ def __init__(self): pass
[docs] def render(self): """Render the element as text.""" return "Placeholder!"
def __str__(self): return self.render()
[docs]class TextData(ASCIIElement): """Prints the value of one particular variable from the base model.""" def __init__(self, model, var_name): """Create a new data renderer.""" self.model = model self.var_name = var_name
[docs] def render(self): return self.var_name + ": " + str(getattr(self.model, self.var_name))
[docs]class TextGrid(ASCIIElement): """Class for creating an ASCII visualization of a basic grid object. By default, assume that each cell is represented by one character, and that empty cells are rendered as ' ' characters. When printed, the TextGrid results in a width x height grid of ascii characters. Properties: grid: The underlying grid object. """ grid = None def __init__(self, grid, converter): """Create a new ASCII grid visualization. Args: grid: The underlying Grid object. converter: function for converting the content of each cell to ascii. Takes the contents of a cell, and returns a single character. """ self.grid = grid self.converter = converter
[docs] def render(self): """What to show when printed.""" viz = "" for y in range(self.grid.height): for x in range(self.grid.width): c = self.grid[y][x] if c is None: viz += " " else: viz += self.converter(c) viz += "\n" return viz