jsnetworkx/node/relabel.js

A graph processing and visualization library for JavaScript (port of NetworkX for Python).

'use strict';

var _Object$assign = require('babel-runtime/core-js/object/assign')['default'];

var _Array$from = require('babel-runtime/core-js/array/from')['default'];

var _interopRequireDefault = require('babel-runtime/helpers/interop-require-default')['default'];

Object.defineProperty(exports, '__esModule', {
  value: true
});
exports.relabelNodes = relabelNodes;
exports.convertNodeLabelsToIntegers = convertNodeLabelsToIntegers;

var _classesDiGraph = require('./classes/DiGraph');

var _classesDiGraph2 = _interopRequireDefault(_classesDiGraph);

var _exceptions = require('./exceptions');

var _internals = require('./_internals');

/**
 * Relabel the nodes of the graph G.
 *
 * ### Examples
 *
 * ```
 * var G = jsnx.pathGraph(3);  // nodes 0-1-2
 * var mapping = {0: 'a', 1: 'b', 2: 'c'};
 * // var mapping = new Map([[0, 'a'], [1, 'b'], [2, 'c']]);
 * var H = jsnx.relabelNodes(G, mapping);
 * H.nodes();
 * // ['a', 'b', 'c']
 * ```
 *
 * Partial in-place mapping
 *
 * ```
 * var G = jsnx.pathGraph(3);  // nodes 0-1-2
 * var mapping = {0: 'a', 1: 'b'};
 * // var mapping = new Map([[0, 'a'], [1, 'b']]);
 * var H = jsnx.relabelNodes(G, mapping, false);
 * H.nodes();
 * // [2, 'b', 'c']
 * ```
 *
 * Mapping as function:
 *
 * ```
 * var G = jsnx.pathGraph(3);
 * var H = jsnx.relabelNodes(G, x => Math.pow(x, 2));
 * H.nodes()
 * // [0, 1, 4]
 * ```
 *
 * ### Notes
 *
 * Only the nodes specified in the mapping will be relabeled.
 *
 * The setting `copy=false` modifies the graph in place.
 * This is not always possible if the mapping is circular.
 * In that case use copy=true.
 *
 * @see #convertNodeLabelsToIntegers
 *
 * @param {Graph} G A JSNetworkX graph
 * @param {(Object|Map|function(Node):Node)} mapping
 *      A dictionary with the old labels as keys and new labels as values.
 *      A partial mapping is allowed.
 * @param {boolean=} optCopy
 *      If `true` return a copy or if `false` relabel the nodes in place.
 * @return {Graph}
 */

function relabelNodes(G, mapping) {
  var optCopy = arguments.length <= 2 || arguments[2] === undefined ? true : arguments[2];

  // you can pass a function f(oldLabel)->newLabel
  // but we'll just make a dictionary here regardless
  var m = mapping;
  if (typeof mapping !== 'function') {
    if (!(0, _internals.isMap)(m)) {
      m = new _internals.Map(m);
    }
  } else {
    m = new _internals.Map((0, _internals.mapIterator)(G.nodesIter(), function (n) {
      return (0, _internals.tuple2)(n, mapping(n));
    }));
  }

  return optCopy ? relabelCopy(G, m) : relabelInplace(G, m);
}

/**
 * @param {Graph} G A JSNetworkX graph
 * @param {Map} mapping
 *      A dictionary with the old labels as keys and new labels as values.
 *      A partial mapping is allowed.
 *
 * @return .Graph}
 * @private
 */
function relabelInplace(G, mapping) {
  var oldLabels = new _internals.Set(mapping.keys());
  var nodes;

  if ((0, _internals.someIterator)(mapping.values(), function (v) {
    return oldLabels.has(v);
  })) {
    // labels sets overlap
    // can we topological sort and still do the relabeling?
    var D = new _classesDiGraph2['default'](mapping);
    D.removeEdgesFrom(D.selfloopEdges());
    try {
      nodes = (0, _internals.topologicalSort)(D);
    } catch (e) {
      if (e instanceof _exceptions.JSNetworkXUnfeasible) {
        throw new _exceptions.JSNetworkXUnfeasible('The node label sets are overlapping and' + ' no ordering can resolve the mapping.' + ' Use copy=True.');
      }
    }
    nodes.reverse(); // reverse topological order
  } else {
    // non-overlapping label sets
    nodes = oldLabels.values();
  }
  var multigraph = G.isMultigraph();
  var directed = G.isDirected();
  var newEdges;

  (0, _internals.forEach)(nodes, function (old) {
    var newMapping;
    if (mapping.has(old)) {
      newMapping = mapping.get(old);
    } else {
      return; // continue
    }

    if (!G.hasNode(old)) {
      throw new _exceptions.JSNetworkXError((0, _internals.sprintf)('Node %j is not in the graph.', old));
    }
    G.addNode(newMapping, G.node.get(old));
    if (multigraph) {
      newEdges = G.edges(old, true, true).map(function (d) {
        return (0, _internals.tuple4c)(newMapping, d[1], d[2], d[3], d);
      });

      if (directed) {
        newEdges = newEdges.concat(G.inEdges(old, true, true).map(function (d) {
          return (0, _internals.tuple4c)(d[0], newMapping, d[2], d[3], d);
        }));
      }
    } else {
      newEdges = G.edges(old, true).map(function (d) {
        return (0, _internals.tuple3c)(newMapping, d[1], d[2], d);
      });

      if (directed) {
        newEdges = newEdges.concat(G.inEdges(old, true).map(function (d) {
          return (0, _internals.tuple3c)(d[0], newMapping, d[2], d);
        }));
      }
    }
    G.removeNode(old);
    G.addEdgesFrom(newEdges);
  });
  return G;
}

/**
 * @param {Graph} G A JSNetworkX graph
 * @param {Map} mapping
 *      A dictionary with the old labels as keys and new labels as values.
 *      A partial mapping is allowed.
 *
 * @return {Graph}
 * @private
 */
function relabelCopy(G, mapping) {
  var H = new G.constructor();
  H.name = '(' + G.name + ')';
  if (G.isMultigraph()) {
    H.addEdgesFrom((0, _internals.mapIterator)(G.edgesIter(null, true, true), function (d) {
      return (0, _internals.tuple4c)(mapping.has(d[0]) ? mapping.get(d[0]) : d[0], mapping.has(d[1]) ? mapping.get(d[1]) : d[1], d[2], (0, _internals.clone)(d[3]), d);
    }));
  } else {
    H.addEdgesFrom((0, _internals.mapIterator)(G.edgesIter(null, true), function (d) {
      return (0, _internals.tuple3c)(mapping.has(d[0]) ? mapping.get(d[0]) : d[0], mapping.has(d[1]) ? mapping.get(d[1]) : d[1], (0, _internals.clone)(d[3]), d);
    }));
  }
  G.node.forEach(function (data, n) {
    return H.addNode(mapping.has(n) ? mapping.get(n) : n, (0, _internals.clone)(data));
  });
  _Object$assign(H.graph, (0, _internals.clone)(G.graph));

  return H;
}

/**
 * Return a copy of G node labels replaced with integers.
 *
 * ### Notes
 *
 * Node and edge attribute data are copied to the new (relabeled) graph.
 *
 * @param {Graph} G A JSNetworkX graph
 * @param {?number=} optFirstLabel
 *      An integer specifying the offset in numbering nodes.
 *      The n new integer labels are numbered firstLabel, ..., n-1+firstLabel.
 * @param {?string=} optOrdering
 *   - "default" : inherit node ordering from `G.nodes()`
 *   - "sorted"  : inherit node ordering from `G.nodes().sort()`
 *   - "increasing degree" : nodes are sorted by increasing degree
 *   - "decreasing degree" : nodes are sorted by decreasing degree
 * @param {?boolean=} optDiscardOldLabels
 *      If true discard old labels. If false, create a node attribute
 *      'oldLabel' to hold the old labels.
 * @return {Graph}
 */

function convertNodeLabelsToIntegers(G) {
  var optFirstLabel = arguments.length <= 1 || arguments[1] === undefined ? 0 : arguments[1];
  var optOrdering = arguments.length <= 2 || arguments[2] === undefined ? 'default' : arguments[2];
  var optDiscardOldLabels = arguments.length <= 3 || arguments[3] === undefined ? true : arguments[3];

  //   This function strips information attached to the nodes and/or
  //   edges of a graph, and returns a graph with appropriate integer
  //   labels. One can view this as a re-labeling of the nodes. Be
  //   warned that the term "labeled graph" has a loaded meaning
  //   in graph theory. The fundamental issue is whether the names
  //   (labels) of the nodes (and edges) matter in deciding when two
  //   graphs are the same. For example, in problems of graph enumeration
  //   there is a distinct difference in techniques required when
  //   counting labeled vs. unlabeled graphs.
  //
  //   When implementing graph
  //   algorithms it is often convenient to strip off the original node
  //   and edge information and appropriately relabel the n nodes with
  //   the integer values 1,..,n. This is the purpose of this function,
  //   and it provides the option (see discardOldLabels variable) to either
  //   preserve the original labels in separate dicts (these are not
  //   returned but made an attribute of the new graph.

  if (typeof optOrdering === 'boolean') {
    optDiscardOldLabels = optOrdering;
    optOrdering = 'default';
  }

  switch (typeof optFirstLabel) {
    case 'string':
      optOrdering = optFirstLabel;
      optFirstLabel = 0;
      break;
    case 'boolean':
      optDiscardOldLabels = optFirstLabel;
      optFirstLabel = 0;
      break;
  }

  var mapping = new _internals.Map();
  var nodes;
  var dvPairs;
  var i;
  var j;
  var l;

  switch (optOrdering) {
    case 'default':
      nodes = G.nodes();
      for (i = 0, j = optFirstLabel, l = nodes.length; i < l; i++, j++) {
        mapping.set(nodes[i], j);
      }
      break;
    case 'sorted':
      nodes = G.nodes();
      nodes.sort();
      for (i = 0, j = optFirstLabel, l = nodes.length; i < l; i++, j++) {
        mapping.set(nodes[i], j);
      }
      break;
    case 'increasing degree':
      dvPairs = _Array$from(G.degreeIter());
      dvPairs.sort(function (a, b) {
        return a[1] - b[1];
      });
      for (i = 0, j = optFirstLabel, l = dvPairs.length; i < l; i++, j++) {
        mapping.set(dvPairs[i][0], j);
      }
      break;
    case 'decreasing degree':
      dvPairs = _Array$from(G.degreeIter());
      dvPairs.sort(function (a, b) {
        return b[1] - a[1];
      });
      for (i = 0, j = optFirstLabel, l = dvPairs.length; i < l; i++, j++) {
        mapping.set(dvPairs[i][0], j);
      }
      break;
    default:
      throw new _exceptions.JSNetworkXError((0, _internals.sprintf)('Unkown node ordering: "%s"', optOrdering));
  }

  var H = relabelNodes(G, mapping);
  H.name = '(' + G.name + ')WithIntLabels';
  if (!optDiscardOldLabels) {
    H.nodeLabels = mapping;
  }
  return H;
}