diff --git a/viewer/index.html b/viewer/index.html
index 826e0ae..90df294 100644
--- a/viewer/index.html
+++ b/viewer/index.html
@@ -1159,12 +1159,30 @@ <h4 class="modal-title">Filter edges by weight</h4>
                         <svg id="edgeWeightChart" width="550" height="200">
                         </svg>
 
+                        <div class="container-fluid">
+                        <div class="row">
+                        <div class="col-lg-6">
+                        <div class='input-group input-group-sm'>
+                            <span class='input-group-btn'>
+                                <button class='btn btn-default'
+                                    onclick='drawEdgeWeightHistogram();'
+                                    type="button" id="setBinCountButton">
+                                    <span class="glyphicon glyphicon-resize-horizontal"
+                                        aria-hidden="true"></span> &nbsp;
+                                    Change histogram bin count
+                                </button>
+                            </span>
+                            <input type='text' class='form-control'
+                                id="binCountInput" value="20">
+                        </div>
+                        </div> <!-- end col 1 -->
+                        <div class="col-lg-6">
                         <!-- NOTE this feature doesn't work very well with
                             collapsing yet -->
                         <div class='input-group input-group-sm'>
                             <span class='input-group-btn'>
-                                <button class='btn btn-default disabled'
-                                    disabled="disabled" onclick='cullEdges();'
+                                <button class='btn btn-default'
+                                    onclick='cullEdges();'
                                     type="button" id="cullEdgesButton">
                                     <span class="glyphicon glyphicon-remove"
                                         aria-hidden="true"></span> &nbsp;
@@ -1172,9 +1190,11 @@ <h4 class="modal-title">Filter edges by weight</h4>
                                 </button>
                             </span>
                             <input type='text' class='form-control'
-                                id="cullEdgesInput" value="0"
-                                disabled="disabled">
+                                id="cullEdgesInput" value="0">
                         </div>
+                        </div> <!-- end col 2 -->
+                        </div> <!-- end row -->
+                        </div> <!-- end container-fluid -->
                     </div> <!-- end modal-body div -->
                     <div class="modal-footer">
                         <button type="button" class="btn btn-default"
diff --git a/viewer/js/xdot2cy.js b/viewer/js/xdot2cy.js
index e3dd193..b0f1cd8 100644
--- a/viewer/js/xdot2cy.js
+++ b/viewer/js/xdot2cy.js
@@ -1387,9 +1387,6 @@ function disableVolatileControls() {
     disableButton("xmlFileselectButton");
     $("#searchInput").prop("disabled", true);
     $("#layoutInput").prop("disabled", true);
-    $("#cullEdgesInput").prop("disabled", true);
-    $("#cullEdgesInput").val("0"); // reset to avoid confusion
-    disableButton("cullEdgesButton");
     disableButton("filterEdgesButton");
     disableButton("reduceEdgesButton");
     disableButton("layoutButton");
@@ -2029,10 +2026,8 @@ function finishDrawComponent(cmpRank, componentNodeCount, componentEdgeCount,
         $("#searchInput").prop("disabled", false);
         $("#layoutInput").prop("disabled", false);
         if (ASM_FILETYPE === "LastGraph" || ASM_FILETYPE === "GML") {
-            // Only enable the edge culling features for graphs that have edge
-            // weights (multiplicity or bundle size)
-            $("#cullEdgesInput").prop("disabled", false);
-            enableButton("cullEdgesButton");
+            // Only enable the edge filtering features for graphs that have
+            // edge weights (multiplicity or bundle size)
             enableButton("filterEdgesButton");
         }
         if (componentEdgeCount > 0) {
@@ -2418,12 +2413,16 @@ function exportGraphView() {
     }
 }
 
-/* Opens the dialog for filtering edges.
- * This code was mostly taken from Mike Bostock's example of d3.js' histogram
- * generation, available at https://gist.github.com/mbostock/3048450.
- */
+/* Opens the dialog for filtering edges. */
 function openEdgeFilteringDialog() {
     $("#edgeFilteringDialog").modal();
+    drawEdgeWeightHistogram();
+}
+
+/* This code was mostly taken from Mike Bostock's example of d3.js' histogram
+ * generation, available at https://gist.github.com/mbostock/3048450.
+ */
+function drawEdgeWeightHistogram() {
     var formatCount = d3.format(",.0f");
     // note could probably find this inline to simplify computation time
     var max = d3.max(COMPONENT_EDGE_WEIGHTS); 
@@ -2442,11 +2441,10 @@ function openEdgeFilteringDialog() {
     var g = chartSvg.append("g")
         .attr("transform","translate(" + margin.left + "," + margin.top + ")");
     var x = d3.scaleLinear().domain([0, max * 1.1]).rangeRound([0, width]);
-    // TODO make this user-selectable
-    var BIN_COUNT = 20;
+    var bin_count = + $("#binCountInput").val();
     var bins = d3.histogram()
         .domain(x.domain())
-        .thresholds(x.ticks(BIN_COUNT))(COMPONENT_EDGE_WEIGHTS);
+        .thresholds(x.ticks(bin_count))(COMPONENT_EDGE_WEIGHTS);
     var y = d3.scaleLinear()
         .domain([0, d3.max(bins, function(b) { return b.length; })])
         .range([height, 0]);
@@ -2487,8 +2485,8 @@ function openEdgeFilteringDialog() {
         .attr("dy", "1em")
         .style("text-anchor", "middle")
         .text("Frequency");
-    // TODO: make BIN_COUNT configurable; ensure that there's space between
-    // every bar; ensure that the y-axis only has ticks for integer values
+    // TODO: ensure that there's space between every bar; ensure that the
+    // y-axis only has ticks for integer values
 }
 
 /* Hides edges below a minimum edge weight (multiplicity or bundle size,