Merge branch 'pete'

This merge updates abpserver to support a full set of operations
including creation / deletion, gates, local complementation, and
measurements through the web interface. So now you can click on qubits
and measure them in X or whatever.

I've tested it but I bet there are bugs -- please raise an issue if you
find one.

Conflicts:
	examples/visualization/grid_2d.py

abp/fancy.py

@@ -43,7 +43,7 @@ class GraphState(graphstate.GraphState, nx.Graph):
             time.sleep(delay)
         except websocket._exceptions.WebSocketTimeoutException:
             print "Timed out ... you might be pushing a bit hard"
-            sys.exit(0)
+            time.sleep(delay)
             #self.ws.close()
             #self.connect_to_server()
 

abp/graphstate.py

@@ -42,6 +42,21 @@ class GraphState(object):
                 for n in range(data):
                     self._add_node(n, vop=vop)
 
+    def add_node(self, *args, **kwargs):
+        """ Add a node """
+        self._add_node(self, *args, **kwargs)
+
+
+    def _del_node(self, node):
+        """ Remove a node. TODO: this is a hack right now! """
+        if not node in self.node:
+            return
+        del self.node[node]
+        for k in self.adj[node]:
+            del self.adj[k][node]
+        del self.adj[node]
+
+
     def _add_node(self, node, **kwargs):
         """ Add a node. By default, nodes are initialized with ``vop=``:math:`I`, i.e. they are in the :math:`|+\\rangle` state.
 
@@ -56,7 +71,10 @@ class GraphState(object):
             fred
 
         """
-        assert not node in self.node, "Node {} already exists".format(v)
+        if node in self.node:
+            print "Warning: node {} already exists".format(node)
+            return
+
         default = kwargs.get("default", "identity")
         self.adj[node] = {}
         self.node[node] = {}
@@ -405,9 +423,6 @@ class GraphState(object):
             >>> with open("graph.json") as f:
                     json.dump(graph.to_json(True), f)
 
-        .. todo::
-            Implement ``from_json()``!
-
         """
         if stringify:
             node = {str(key): value for key, value in self.node.items()}
@@ -417,6 +432,13 @@ class GraphState(object):
         else:
             return {"node": self.node, "adj": self.adj}
 
+    def from_json(self, data):
+        """ Construct the graph from JSON data 
+        :param data: JSON data to be read.
+        """
+        self.node = data["node"]
+        self.adj = data["adj"]
+
     def to_state_vector(self):
         """ Get the full state vector corresponding to this stabilizer state. Useful for debugging, interface with other simulators.
             This method becomes very slow for more than about ten qubits!

abp/static/index.html

@@ -29,16 +29,14 @@
 <div id=node_name></div>
 <ul>
     <li id=node_vop></li>
-    <!--<li><a href="#">Measure in X</a></li>-->
-    <!--<li><a href="#">Measure in Y</a></li>-->
-    <!--<li><a href="#">Measure in Z</a></li>-->
-    <!--<li><a href="#">Act Hadamard</a></li>-->
-    <!--<li><a href="#">Act Phase</a></li>-->
-    <!--<li><a href="#" onclick="editor.localComplementation()">Invert neighbourhood</a></li>-->
-    <!--<li>-->
-    <!--<a href="#">IA</a>-->
-    <!--<a href="#">IB</a>-->
-    <!--</li>-->
+    <li>Measure in 
+    <a href="#" onclick="editor.measureX()">X</a> / 
+    <a href="#" onclick="editor.measureY()">Y</a> / 
+    <a href="#" onclick="editor.measureZ()">Z</a></li>
+    <li>Act 
+    <a href="#" onclick="editor.hadamard()">Hadamard</a> / 
+    <a href="#" onclick="editor.phase()">Phase</a></li>
+    <li><a href="#" onclick="editor.localComplementation()">Invert neighbourhood</a></li>
     <li><a href="#" onclick="editor.deleteNode()">Delete</a></li>
 </ul>
 </div>

abp/static/main.css

@@ -26,6 +26,9 @@ html, body { margin: 0; padding: 0; overflow: hidden; font-size:  10pt; font-fam
     font-size: 9pt;
 }
 
+#node_name {
+    font-size: 12pt;
+}
 
 #node_data {
     background-color: black;

abp/static/scripts/anders_briegel.js

@@ -41,80 +41,19 @@ abj.has_edge = function(a, b) {
     return Object.prototype.hasOwnProperty.call(abj.adj[a], b);
 };
 
-abj.toggle_edge = function(a, b) {
-    if (abj.has_edge(a, b)) {
-        abj.del_edge(a, b);
-    } else {
-        abj.add_edge(a, b);
-    }
-};
-
-abj.get_swap = function(node, avoid) {
-    for (var i in abj.adj[node]) {
-        if (i != avoid) {
-            return i;
-        }
-    }
-    return avoid;
-};
-
-abj.remove_vop = function(node, avoid) {
-    var swap_qubit = abj.get_swap(node, avoid);
-    var decomposition = tables.decompositions[abj.node[node].vop];
-    for (var i = decomposition.length - 1; i >= 0; --i) {
-        var v = decomposition[i];
-        abj.local_complementation(v == "x" ? node : swap_qubit);
-    }
-};
-
-abj.local_complementation = function(node) {
-    // TODO: inefficient
-    var done = {};
-    for (var i in abj.adj) {
-        for (var j in abj.adj[i]) {
-            var name = i>j ? [i,j] : [j,i];
-            if (done[name]===false){
-                abj.toggle_edge(i, j);
-                done[name] = true;
-            }
-        }
-        abj.node[i].vop = tables.times_table[abj.node[i].vop][6];
-    }
-    abj.node[node].vop = tables.times_table[abj.node[node].vop][14];
-};
-
-abj.act_local_rotation = function(node, operation) {
-    var rotation = tables.clifford[operation];
-    abj.node[node].vop = tables.times_table[rotation][abj.node[node].vop];
-};
-
-abj.act_hadamard = function(node) {
-    abj.act_local_rotation(node, 10);
-};
-
 abj.is_sole_member = function(group, node) {
     // TODO: this is slow as heck
     var keys = Object.keys(group);
     return keys.length == 1 && keys[0] == node;
 };
 
-abj.act_cz = function(a, b) {
-    if (abj.is_sole_member(abj.adj[a], b)) {
-        abj.remove_vop(a, b);
-    }
-    if (abj.is_sole_member(abj.adj[b], a)) {
-        abj.remove_vop(b, a);
-    }
-    if (abj.is_sole_member(abj.adj[a], b)) {
-        abj.remove_vop(a, b);
-    }
-    var edge = abj.has_edge(a, b);
-    var new_state = tables.cz_table[edge ? 1 : 0][abj.node[a].vop][abj.node[b].vop];
-    abj.node[a].vop = new_state[1];
-    abj.node[b].vop = new_state[2];
-    if (new_state[0] != edge) {
-        abj.toggle_edge(a, b);
-    }
+abj.update = function(newState) {
+    abj.node = newState.node;
+    abj.adj = newState.adj;
+};
+
+abj.order = function(){
+    return Object.keys(abj.node).length;
 };
 
 abj.edgelist = function() {
@@ -131,18 +70,4 @@ abj.edgelist = function() {
     return output;
 };
 
-abj.log_graph_state = function() {
-    console.log(JSON.stringify(abj.node));
-    console.log(JSON.stringify(abj.adj));
-};
-
-abj.update = function(newState) {
-    abj.node = newState.node;
-    abj.adj = newState.adj;
-};
-
-abj.order = function(){
-    return Object.keys(abj.node).length;
-};
-
 

abp/static/scripts/editor.js

@@ -32,14 +32,10 @@ editor.onFreeMove = function() {
 };
 
 editor.focus = function(node) {
-    editor.grid.position.copy(abj.node[node].position);
-    gui.controls.target.copy(abj.node[node].position);
     gui.hideNodeMessage();
     editor.selection = node;
-    gui.serverMessage("Selected node " + node + ".");
-    node_name.innerHTML = "Node " + node;
-    node_data.className = "visible";
-    node_vop.innerHTML = "VOP: " + abj.node[node].vop;
+
+    //gui.serverMessage("Selected node " + node + ".");
 };
 
 editor.addQubitAtPoint = function(point) {
@@ -47,19 +43,13 @@ editor.addQubitAtPoint = function(point) {
         return;
     }
     point.round();
-
-    // Check for clashes
-    for (var node in abj.node) {
-        var delta = new THREE.Vector3();
-        delta.subVectors(abj.node[node].position, point);
-        if (delta.length()<0.1){ return; }
+    var new_node = Math.floor(point.x) + "," + Math.floor(point.y) + "," + Math.floor(point.z);
+    if (Object.prototype.hasOwnProperty.call(abj.node, new_node)) {
+        gui.serverMessage("Node " + new_node +" already exists.");
+        return;
     }
-
-    // TODO: This SUCKS
-    var new_node = point.x + "." + point.y + "." + point.z;
-    abj.add_node(new_node, { position: point, vop:0 });
+    websocket.edit({action:"create", name:new_node, position: point});
     editor.focus(new_node);
-    graph.update();
     gui.serverMessage("Created node " + new_node +".");
 };
 
@@ -67,6 +57,12 @@ editor.onClick = function() {
     var found = editor.findNodeOnRay(mouse.ray);
     if (found) {
         editor.focus(found);
+        var node=found;
+        editor.grid.position.copy(abj.node[node].position);
+        gui.controls.target.copy(abj.node[node].position);
+        node_name.innerHTML = "Node " + node;
+        node_data.className = "visible";
+        node_vop.innerHTML = "VOP: " + abj.node[node].vop;
     } else {
         var intersection = mouse.ray.intersectPlane(editor.plane);
         if (intersection !== null) {
@@ -80,10 +76,10 @@ editor.onShiftClick = function() {
     if (found === undefined){ return; }
     if (editor.selection === undefined){ return; }
     if (found === editor.selection){ return; }
-    abj.act_cz(found, editor.selection);
-    editor.focus(found);
+    //abj.act_cz(found, editor.selection);
+    websocket.edit({action:"cz", start:found, end:editor.selection});
     gui.serverMessage("Acted CZ between " + found + " & " + editor.selection + ".");
-    graph.update();
+    editor.focus(found);
 };
 
 editor.onCtrlClick = function() {
@@ -91,9 +87,8 @@ editor.onCtrlClick = function() {
     if (found === undefined){ return; }
     if (editor.selection === undefined){ return; }
     editor.focus(found);
-    abj.act_hadamard(found);
+    websocket.edit({action:"hadamard", node:found});
     gui.serverMessage("Acted H on node " + found + ".");
-    graph.update();
 };
 
 
@@ -147,16 +142,47 @@ editor.findNodeOnRay = function(ray) {
 
 editor.deleteNode = function() {
     if (editor.selection === undefined){ return; }
-    abj.del_node(editor.selection);
-    graph.update();
+    websocket.edit({action:"delete", node:editor.selection});
     gui.serverMessage("Deleted node " + editor.selection + ".");
     editor.selection = undefined;
     node_data.className = "hidden";
 };
 
+//TODO: loadsa space for DRY here
+
+editor.hadamard = function() {
+    if (editor.selection === undefined){ return; }
+    websocket.edit({action:"hadamard", node:editor.selection});
+    gui.serverMessage("Acted Hadamard on node " + editor.selection + ".");
+};
+
+editor.phase = function() {
+    if (editor.selection === undefined){ return; }
+    websocket.edit({action:"phase", node:editor.selection});
+    gui.serverMessage("Acted phase on node " + editor.selection + ".");
+};
+
+editor.measureX = function() {
+    if (editor.selection === undefined){ return; }
+    websocket.edit({action:"measure", node:editor.selection, basis:"x"});
+    gui.serverMessage("Measured node " + editor.selection + " in X.");
+};
+
+editor.measureY = function() {
+    if (editor.selection === undefined){ return; }
+    websocket.edit({action:"measure", node:editor.selection, basis:"y"});
+    gui.serverMessage("Measured node " + editor.selection + " in Y.");
+};
+
+editor.measureZ = function() {
+    if (editor.selection === undefined){ return; }
+    websocket.edit({action:"measure", node:editor.selection, basis:"z"});
+    gui.serverMessage("Measured node " + editor.selection + " in z.");
+};
+
 editor.localComplementation = function() {
     if (editor.selection === undefined){ return; }
+    websocket.edit({action:"localcomplementation", node:editor.selection});
     abj.local_complementation(editor.selection);
-    graph.update();
     gui.serverMessage("Inverted neighbourhood of " + editor.selection + ".");
 };

abp/static/scripts/graph.js

@@ -47,6 +47,23 @@ graph.update = function(newState) {
         edges.add(newEdge);
     }
 
+    if (editor.selection) {
+        console.log(editor.selection);
+        var node = editor.selection;
+        if (Object.prototype.hasOwnProperty.call(abj.node, node)) {
+            editor.grid.position.copy(abj.node[node].position);
+            gui.controls.target.copy(abj.node[node].position);
+            node_name.innerHTML = "Node " + node;
+            node_data.className = "visible";
+            node_vop.innerHTML = "VOP: " + abj.node[node].vop;
+        } else {
+            editor.selection = undefined;
+            node_data.className = "hidden";
+        }
+    } else {
+        node_data.className = "hidden";
+    } 
+
     var particles = new THREE.Points(geometry, materials.qubit);
     var object = new THREE.Object3D();
     object.name = "graphstate";
@@ -54,5 +71,6 @@ graph.update = function(newState) {
     object.add(edges);
     gui.scene.add(object);
     gui.render();
+
 };
 

abp/static/scripts/materials.js

@@ -1,7 +1,7 @@
 var materials = {};
 
 var curveProperties = {
-    splineDensity: 1,
+    splineDensity: 10,
     curvature: 20
 };
 

abp/static/scripts/tests.js

@@ -1,4 +0,0 @@
-QUnit.test( "Adding nodes", function( assert ) {
-    abj.add_node(0);
-    assert.ok(abj.node[0].vop === 10, JSON.stringify(abj.node));
-});

abp/static/scripts/websocket.js

@@ -1,16 +1,20 @@
 var websocket = {};
+websocket.update = undefined;
 
 websocket.connect = function(update) {
-    var ws = new WebSocket("ws://localhost:5000");
-    ws.onopen = function(evt) {
+    websocket.ws = new WebSocket("ws://localhost:5000");
+    if (update){
+        websocket.update = update;
+    }
+    websocket.ws.onopen = function(evt) {
         gui.serverMessage("Connected to server.");
     };
 
-    ws.onerror = function(err) {
+    websocket.ws.onerror = function(err) {
         gui.serverMessage("Could not connect to server.");
     };
 
-    ws.onmessage = function(evt) {
+    websocket.ws.onmessage = function(evt) {
         json = JSON.parse(evt.data);
         for (var i in json.node) {
             var pos = json.node[i].position;
@@ -19,10 +23,14 @@ websocket.connect = function(update) {
                 json.node[i].vop = 0;
             }
         }
-        update(json);
+        websocket.update(json);
     };
 
-    ws.onclose = function(evt) {
+    websocket.ws.onclose = function(evt) {
         gui.serverMessage("No connection to server. <a href='#' onclick='javascript:websocket.connect()'>Reconnect</a>.", true);
     };
 };
+
+websocket.edit = function (data) {
+    websocket.ws.send("edit:"+JSON.stringify(data));
+};

bin/abpserver

@@ -12,17 +12,55 @@ import os, sys, threading
 import webbrowser
 import argparse
 import abp
+import json
 from pkg_resources import resource_filename
+from pprint import pprint
+import time
 
 clients = []
+local_state = abp.GraphState()
+
+def process_edit(edit, client, server):
+    action = edit["action"]
+
+    pprint(edit)
+
+    if action == "create":
+        local_state.add_qubit(edit["name"], position=edit["position"], vop=0)
+    elif action == "cz":
+        local_state.act_cz(edit["start"], edit["end"])
+    elif action == "hadamard":
+        local_state.act_hadamard(edit["node"])
+    elif action == "phase":
+        local_state.act_local_rotation(edit["node"], "phase")
+    elif action == "delete":
+        local_state._del_node(edit["node"])
+    elif action == "localcomplementation":
+        local_state.local_complementation(edit["node"])
+    elif action == "measure":
+        local_state.measure(edit["node"], "p"+edit["basis"])
+    else:
+        pass
+
+    #server.send_message(client, json.dumps(local_state.to_json()))
+    server.send_message_to_all(json.dumps(local_state.to_json()))
 
 def new_message(client, server, message):
-    print "Received update from client {}.".format(client["id"])
-    server.send_message_to_all(message)
+    if message.startswith("edit:"):
+        edit = json.loads(message[5:])
+        process_edit(edit, client, server)
+    else:
+        print "Received update from python {}.".format(client["id"])
+        print message
+        local_state.from_json(json.loads(message))
+        print local_state
+        server.send_message_to_all(message)
 
 def new_client(client, server):
     print "Client {} connected.".format(client["id"])
     clients.append(client)
+    print "Sent state of {} nodes to client {}".format(local_state.order(), client["id"])
+    server.send_message(client, json.dumps(local_state.to_json()))
 
 def client_left(client, server):
     print "Client {} disconnected.".format(client["id"])

examples/visualization/grid_2d.py

@@ -2,13 +2,22 @@ from abp.fancy import GraphState
 from abp.util import xyz
 import itertools
 
-psi = GraphState()
-grid = itertools.product(range(10), range(10))
-for i, (x, y) in enumerate(grid):
-    psi.add_qubit(i, position=xyz(x, y, 0), vop=0)
+def grid_2d(width, height):
+    """ Make a 2D grid """
+    psi = GraphState()
+    grid = list(itertools.product(range(width), range(height)))
 
-for i in range(50):
-    psi.act_cz(i, i+1)
+    for x, y in grid:
+        psi.add_qubit((x, y), position=xyz(x, y, 0), vop=0)
 
-psi.update()
+    for x, y in grid:
+        if x<width-1: psi.act_cz((x, y), (x+1, y))
+        if y<height-1: psi.act_cz((x, y), (x, y+1))
+
+    return psi
+
+
+if __name__ == '__main__':
+    psi = grid_2d(5, 5)
+    psi.update()
 

examples/visualization/lattice_2d.py

@@ -34,10 +34,11 @@ nodes, edges = lattice(square_unit_cell, (10, 10))
 
 psi = GraphState()
 for node in nodes:
-    psi.add_node(str(node), position=xyz(node[0], node[1]))
+    psi.add_qubit(str(node), position=xyz(node[0], node[1]))
     psi.act_hadamard(str(node))
     psi.update(0.1)
 
 for edge in edges:
     psi.act_cz(str(edge[0]), str(edge[1]))
+psi.update(0.1)
 

examples/visualization/lattice_3d.py

@@ -45,9 +45,10 @@ nodes, edges = lattice(threedee_unit_cell, (3, 3, 3))
 
 psi = GraphState()
 for node in nodes:
-    psi.add_node(str(node), position=xyz(*node))
+    psi.add_qubit(str(node), position=xyz(*node))
     psi.act_hadamard(str(node))
 
 for edge in edges:
     psi.act_cz(str(edge[0]), str(edge[1]))
+psi.update()
 

tests/test_graphstate.py

@@ -131,3 +131,10 @@ def test_from_nx():
 
     psi = GraphState(nx.Graph(((0, 1),)))
 
+def test_del_node():
+    """ Test deleting nodes """
+    g = GraphState(10)
+    g.act_circuit(mock.random_stabilizer_circuit())
+    g._del_node(0)
+    assert g.order() == 9
+

tests/test_json.py

@@ -0,0 +1,31 @@
+import mock
+import abp
+
+def test_json():
+    """ Test to_json and from_json """
+    a = mock.named_node_graph()
+    j = a.to_json()
+
+    b = abp.GraphState()
+    b.from_json(j)
+    assert a == b
+
+
+def test_json_again():
+    """ Test to_json and from_json """
+    # Make a random graph
+    a = abp.GraphState(10)
+    a.act_circuit(mock.random_graph_circuit())
+
+    # Dump it to JSON
+    j = a.to_json()
+
+    # Reconstruct from JSON
+    b = abp.GraphState()
+    b.from_json(j)
+
+    # Check equality
+    assert a == b
+
+
+