histograms for category

lib/torque/leaflet/torque.js

@@ -217,43 +217,11 @@ L.TorqueLayer = L.CanvasLayer.extend({
     this.provider.getHistogramForTiles(varName, start, end, bins, tiles, callback);
   },
 
-  getHistogram:function(variable,callback,noBins){
+  getCategoriesForVisibleRegion: function(varName, callback){
-    var type= this.provider._mapping[variable].type
+    var tiles = this.visibleTiles();
-    if(type=='float'){
+    this.provider.getCategoriesForTiles(varName, tiles, callback);
-      callback(this.histogramForRangeVariable(variable,noBins))
-    }
-    else if(type='cat'){
-      callback(this.histogramForCatVariable(variable))
-    }
-    return this
   },
 
-  histogramForCatVariable:function(variable){
-    var result = {}
-    this.valuesForCatVariable(variable).forEach(function(point){
-      Object.keys(point).forEach(function(key){
-        result[key] = result[key] || 0
-        result[key] += point[key]
-      })
-    })
-    return result
-  },
-  histogramForRangeVariable:function(variable,noBins){
-    noBins = noBins || 10
-
-    var vals = this.valuesForRangeVariable(variable)
-
-    var min  = Math.min.apply(null, vals)
-    var max  = Math.max.apply(null, vals)
-    var binSize  = (max-min)/noBins
-    var result = []
-    vals.forEach(function(val){
-      var bin = (val -min)/binSize
-      result[bin]= result[bin] || 0
-      result[bin] +=  val
-    })
-    return result
-  },
   onAdd: function (map) {
     map.on({
       'zoomend': this._clearCaches,

lib/torque/provider/filterableJson.js

@@ -711,19 +711,48 @@ var Profiler = require('../profiler');
       });
     },
 
-    getCatHistogramForTiles: function(varName, tiles, table, callback){
+    getCategoriesForTiles: function(varName, tiles, callback){
+      var tilesFilter = this._generateBoundsQuery(tiles);
+      this.tablesForFilter(tilesFilter, function(tables) {
+        // select the table with less than 100k records
+        var table = tables.filter(function(f) {
+          return f.nrows < 50000;
+        })
+        table = table.length ? table[0].table_name: this.options.overview_tables[this.options.overview_tables.length - 1]
+        this._getCategoriesForTiles(varName, tiles, table, callback)
+      }.bind(this));
+    },
+
+    _getCategoriesForTiles: function(varName, tiles, table, callback){
 
       var sql = [
-        'select {varName}, count(1) from {table} where ({bounds}) {filters} group by 1 order by 2 desc limit {num_cats}',
+        'select {varName} category, count(1) as "value" from {table} {tiles} where {bounds} {filters} group by 1 order by 2 desc limit {num_cats}',
       ]
 
       var filters = this._generateFiltersSQL(false, [varName]) ?  " and "+ this._generateFiltersSQL(false, [varName]) : ""
 
+      var tiles_query = tiles.map(function (t, i) {
+        return "xyz2range(" + t.x + "," + t.y + "," + t.z + ") q" + i;
+      }).join(',')
+
+      if (tiles_query) {
+        tiles_query = "," + tiles_query
+      }
+
+      var bounds = tiles.map(function(t, i) {
+        return format("(quadkey between q{i}.min and q{i}.max)", { i: i })
+      }).join('or')
+
+      if (bounds) {
+        bounds = '(' + bounds + ')';
+      }
+
       var query = format(sql.join('\n'), {
         varName: varName,
         table: table,
         filters: filters,
-        bounds: this._generateBoundsQuery(tiles),
+        tiles: tiles_query,
+        bounds: bounds,
         num_cats: 20
       });