Index of /emile/models/graphPrototype

Name	Last modified	Size

Parent Directory		-
run.e	2012-12-03 16:50	98
nodeset2.js	2013-02-13 03:30	13K
DrawFuncEden.js-e	2012-12-04 14:59	929

html(" Hui Zhu's Graph Prototype model

Hui Zhu's model demonstrates one way in which the functionality that currently exists in EDEN may be replicated in JS-EDEN. The objective is to enable the construction of graphs in JS-EDEN in something like the way that Charlie Care did by creating a graph.eden add-on (cf. the implementation of the DMT within EDEN, as illustrated in one of the lab sessions). Hui's Graph Prototype model is still at an early stage of development, and uses JS-EDEN in a somewhat experimental way. In its present form, it has limitations. For instance, it is only suitable for specifying a single graph structure (which potentially suffices for an application such as making a DMT within JS-EDEN). It is nonetheless instructive to study the code, and understand some of the issues involved in its construction.

To load the model, enter

include(\"models/graphPrototype/run.e\");

into the EDEN Interpreter Window.

To test out the model, you can define a graph g as follows:

g is Graph(\"myGraph\");

and add nodes and edges to the graph g by using the addNode and addEdge constructors. For instance:

addNode(g, \"a\"); addNode(g, \"b\"); addEdge(g, \"d\", \"b\");

adds nodes a, b and d to the graph g, and connects d to b by a directed edge.

Note that these constructors introduce JS-EDEN observables to represent e.g. the x and y coordinates of nodes, and the colour of each edge. This makes it possible to set up and manipulate the graph via JS-EDEN without resorting to using JScript directly. For instance:

pdx = 100; coldb = \"green\";graph

relocates the node d of the graph g, and displays the edge db in green.

To inspect the code for the graph prototype model, consult the files at

http://jseden.dcs.warwick.ac.uk/emile/models/graphPrototype/

The file nodeset2.js contains the JScript that supports the JS-EDEN graph structure. Much of the complexity in the code for a prototype edge derives from the addition of arrows. The complementary file DrawFuncEden.js-e defines Graph as a drawable object in JS-EDEN and automatically manages the picture observable for the graph. The JScript code within the JS-EDEN Graph() function illustrates the use of prototyping from a base graph, but this only clones a pointer to a prototype graph structure, and hence is suitable only for setting up one independent graph structure in JS-EDEN. Further exploration, comprehension and refinement these files is left as an optional exercise to the interested reader.

");