Basic functionality¶

In this demo you will learn how to load a graph, generate its plot and search through it.

Create and examine a graph¶

First, load a structural system model

model = g007();

Create a new GraphInterface object to host the graph

initialGraph = GraphInterface();

Then, read the model

initialGraph.readModel(model);

Build the adjacency matrices

initialGraph.createAdjacency();

The initial graph has a GraphBipartite, a Registry and an Adjacency member

disp(initialGraph);

GraphInterface with properties:

      graph: [1x1 GraphBipartite]
        reg: [1x1 Registry]
 idProvider: [1x1 IDProvider]
  adjacency: [1x1 Adjacency]
formulaList: []
       name: 'g007'

The graph member contains all of the graph element arrays

disp(initialGraph.graph);

GraphBipartite with properties:

equations: [1x17 Equation]
variables: [1x19 Variable]
    edges: [1x45 Edge]
     name: 'g007'
   coords: []
       gi: [1x1 GraphInterface]
  numVars: 19
   numEqs: 17
 numEdges: 45

The adjacency member contains the bidirectional, the equation-to-veriable and variable-to-equation adjacency matrices

disp(initialGraph.adjacency);

Adjacency with properties:

      gi: [1x1 GraphInterface]
      BD: [36x36 double]
 numVars: 19
  numEqs: 17
 eqNames: []
   eqIds: []
varNames: []
  varIds: []
     E2V: [17x19 double]
     V2E: [19x17 double]

Create a new plotter object

plotter = Plotter(initialGraph);

Create a dot graph and compile it

plotter.plotDot('initial');

The output .ps image is in the g008 folder. This is the resulting image. Open it in a new tab to view it in full resolution.

Note how every equation is a rectrangle and every variable is a circle. All graph elements display their ID below them.

Graph elements discovery¶

Get the IDs of all the variables in the graph

variableIdArray = initialGraph.getVariables()

variableIdArray =

 2     4     6     8    10    13    15    19    22    28    32    35    38    41    44    47    71    75    79

Get the names of all the variables

variableNames = initialGraph.getAliasById(variableIdArray)

variableNames =

Columns 1 through 12

'dot_x1'    'x1'    'x3'    'x4'    'x6'    'dot_x2'    'x2'    'x7'    'dot_x3'    'dot_x4'    'dot_x5'    'x5'

Columns 13 through 19

'dot_x6'    'u1'    'dot_x7'    'u2'    'y1'    'y2'    'y3'

Get the equations which use the first variable

equ1 = initialGraph.getEquations(variableIdArray(1))

equ1 =

 1    49

Get the edge between the first variable and the first equation

edge1 = initialGraph.getEdgeIdByVertices(equ1(1),variableIdArray(1))

edge1 =

 3

Discover elements by property¶

Find all of the known variables

knownVars = initialGraph.getVariablesKnown;
initialGraph.getAliasById(knownVars)

ans =

'u1'    'u2'    'y1'    'y2'    'y3'

Find all of the inputs

inputVars = initialGraph.getVarIdByProperty('isInput');
initialGraph.getAliasById(inputVars)

ans =

'u1'    'u2'