Merge pull request #274 from pelias/243-reverse-confidence-scores

243 reverse confidence scores

middleware/confidenceScoreReverse.js

@@ -0,0 +1,68 @@
+var logger = require('pelias-logger').get('api');
+var _ = require('lodash');
+
+// these are subjective terms, but wanted to add shortcuts to denote something
+//  about importance
+var SCORES = {
+  EXACT: 1.0,
+  EXCELLENT: 0.9,
+  GOOD: 0.8,
+  OKAY: 0.7,
+  POOR: 0.6,
+  NONE: 0.5,
+  INVALID: 0.0
+};
+
+var BUCKETS = {
+  _1_METER: 1,
+  _10_METERS: 10,
+  _100_METERS: 100,
+  _250_METERS: 250,
+  _1_KILOMETER: 1000
+};
+
+function setup() {
+  return computeScores;
+}
+
+function computeScores(req, res, next) {
+  // do nothing if no result data set
+  if (!res.data || !res.data) {
+    return next();
+  }
+
+  // loop through data items and determine confidence scores
+  res.data = res.data.map(computeConfidenceScore);
+
+  next();
+}
+
+function computeConfidenceScore(hit) {
+  // non-number or invalid distance should be given confidence 0.0
+  if (!_.isFinite(hit.distance) || hit.distance < 0) {
+    hit.confidence = SCORES.INVALID;
+    return hit;
+  }
+
+  var distance = hit.distance * 1000.0;
+
+  // figure out which range the distance lies in and assign confidence accordingly
+  if (distance < BUCKETS._1_METER) {
+    hit.confidence = SCORES.EXACT;
+  } else if (distance < BUCKETS._10_METERS) {
+    hit.confidence = SCORES.EXCELLENT;
+  } else if (distance < BUCKETS._100_METERS) {
+    hit.confidence = SCORES.GOOD;
+  } else if (distance < BUCKETS._250_METERS) {
+    hit.confidence = SCORES.OKAY;
+  } else if (distance < BUCKETS._1_KILOMETER) {
+    hit.confidence = SCORES.POOR;
+  } else {
+    hit.confidence = SCORES.NONE;
+  }
+
+  return hit;
+
+}
+
+module.exports = setup;

middleware/distance.js

@@ -1,4 +1,5 @@
 var geolib = require('geolib');
+var check = require('check-types');
 
 
 function setup() {
@@ -13,14 +14,20 @@ function computeDistances(req, res, next) {
     return next();
   }
 
-  if ( !(req.clean.hasOwnProperty('lat') && req.clean.hasOwnProperty('lon')) ) {
+  if (!(check.number(req.clean['point.lat']) &&
+        check.number(req.clean['point.lon']))) {
     return next();
   }
 
+  var point = {
+    latitude: req.clean['point.lat'],
+    longitude: req.clean['point.lon']
+  };
+
   res.data.forEach(function (place) {
     // the result of getDistance is in meters, so convert to kilometers
     place.distance = geolib.getDistance(
-      { latitude: req.clean.lat, longitude: req.clean.lon },
+      point,
       { latitude: place.center_point.lat, longitude: place.center_point.lon }
     ) / 1000;
   });

routes/v1.js

@@ -29,6 +29,7 @@ var controllers     = {
 var postProc = {
   distances: require('../middleware/distance'),
   confidenceScores: require('../middleware/confidenceScore'),
+  confidenceScoresReverse: require('../middleware/confidenceScoreReverse'),
   renamePlacenames: require('../middleware/renamePlacenames'),
   geocodeJSON: require('../middleware/geocodeJSON'),
   sendJSON: require('../middleware/sendJSON')
@@ -75,8 +76,10 @@ function addRoutes(app, peliasConfig) {
       sanitisers.reverse.middleware,
       middleware.types,
       controllers.search(undefined, reverseQuery),
-      // TODO: add confidence scores
       postProc.distances(),
+      // reverse confidence scoring depends on distance from origin
+      //  so it must be calculated first
+      postProc.confidenceScoresReverse(),
       postProc.renamePlacenames(),
       postProc.geocodeJSON(peliasConfig, base),
       postProc.sendJSON

test/unit/middleware/confidenceScoreReverse.js

@@ -0,0 +1,178 @@
+var confidenceScoreReverse = require('../../../middleware/confidenceScoreReverse')();
+
+module.exports.tests = {};
+
+module.exports.tests.confidenceScoreReverse = function(test, common) {
+  test('res without results should not throw exception', function(t) {
+    var res = {};
+
+    try {
+      confidenceScoreReverse(null, res, function() {});
+    }
+    catch (e) {
+      t.fail('an exception should not have been thrown');
+    }
+    finally {
+      t.end();
+    }
+
+  });
+
+  test('res.results without data should not throw exception', function(t) {
+    var res = {
+      results: {}
+    };
+
+    try {
+      confidenceScoreReverse(null, res, function() {});
+    }
+    catch (e) {
+      t.fail('an exception should not have been thrown');
+    }
+    finally {
+      t.end();
+    }
+
+  });
+
+  test('0m <= distance < 1m should be given score 1.0', function(t) {
+    var res = {
+      data: [
+        { distance: 0.0000 / 1000.0 },
+        { distance: 0.9999 / 1000.0 }
+      ]
+    };
+
+    confidenceScoreReverse(null, res, function() {
+      t.equal(res.data[0].confidence, 1.0, 'score should be exact confidence');
+      t.equal(res.data[1].confidence, 1.0, 'score should be exact confidence');
+      t.end();
+    });
+
+  });
+
+  test('1m <= distance < 10m should be given score 0.9', function(t) {
+    var res = {
+      data: [
+        { distance: 1.0000 / 1000.0 },
+        { distance: 9.9999 / 1000.0 }
+      ]
+    };
+
+    confidenceScoreReverse(null, res, function() {
+      t.equal(res.data[0].confidence, 0.9, 'score should be excellent confidence');
+      t.equal(res.data[1].confidence, 0.9, 'score should be excellent confidence');
+      t.end();
+    });
+
+  });
+
+  test('10m <= distance < 100m should be given score 0.8', function(t) {
+    var res = {
+      data: [
+        { distance: 10.0000 / 1000.0 },
+        { distance: 99.9999 / 1000.0 }
+      ]
+    };
+
+    confidenceScoreReverse(null, res, function() {
+      t.equal(res.data[0].confidence, 0.8, 'score should be good confidence');
+      t.equal(res.data[1].confidence, 0.8, 'score should be good confidence');
+      t.end();
+    });
+
+  });
+
+  test('100m <= distance < 250m should be given score 0.7', function(t) {
+    var res = {
+      data: [
+        { distance: 100.0000 / 1000.0 },
+        { distance: 249.9999 / 1000.0 }
+      ]
+    };
+
+    confidenceScoreReverse(null, res, function() {
+      t.equal(res.data[0].confidence, 0.7, 'score should be okay confidence');
+      t.equal(res.data[1].confidence, 0.7, 'score should be okay confidence');
+      t.end();
+    });
+
+  });
+
+  test('250m <= distance < 1000m should be given score 0.6', function(t) {
+    var res = {
+      data: [
+        {distance: 250.0000 / 1000.0},
+        {distance: 999.9999 / 1000.0}
+      ]
+    };
+
+    confidenceScoreReverse(null, res, function() {
+      t.equal(res.data[0].confidence, 0.6, 'score should be poor confidence');
+      t.equal(res.data[1].confidence, 0.6, 'score should be poor confidence');
+      t.end();
+    });
+
+  });
+
+  test('distance >= 1000m should be given score 0.5', function(t) {
+    var res = {
+      data: [
+        {distance: 1000.0 / 1000.0},
+        {distance: 2000.0 / 1000.0}
+      ]
+    };
+
+    confidenceScoreReverse(null, res, function() {
+      t.equal(res.data[0].confidence, 0.5, 'score should be least confidence');
+      t.equal(res.data[1].confidence, 0.5, 'score should be least confidence');
+      t.end();
+    });
+
+  });
+
+  test('distance < 0 (invalid) should be given score 0.0', function(t) {
+    var res = {
+      data: [
+        { distance: -1.0000 / 1000.0 }
+      ]
+    };
+
+    confidenceScoreReverse(null, res, function() {
+      t.equal(res.data[0].confidence, 0.0, 'score should be 0.0 confidence');
+      t.end();
+    });
+
+  });
+
+  test('non-number-type (invalid) distance should be given score 0.0', function(t) {
+    var res = {
+      data: [
+        {},
+        {distance: []},
+        {distance: {}},
+        {distance: 'this is not a number'}
+      ]
+    };
+
+    confidenceScoreReverse(null, res, function() {
+      t.equal(res.data[0].confidence, 0.0, 'score should be 0.0 confidence');
+      t.equal(res.data[1].confidence, 0.0, 'score should be 0.0 confidence');
+      t.equal(res.data[2].confidence, 0.0, 'score should be 0.0 confidence');
+      t.equal(res.data[3].confidence, 0.0, 'score should be 0.0 confidence');
+      t.end();
+    });
+
+  });
+
+};
+
+module.exports.all = function (tape, common) {
+  function test(name, testFunction) {
+    return tape('[middleware] confidenceScoreReverse: ' + name, testFunction);
+  }
+
+  for( var testCase in module.exports.tests ){
+    module.exports.tests[testCase](test, common);
+  }
+};

test/unit/middleware/distance.js

@@ -6,8 +6,8 @@ module.exports.tests.computeDistance = function(test, common) {
   test('valid lat/lon and results', function(t) {
     var req = {
       clean: {
-        lat: 45,
-        lon: -77
+        'point.lat': 45,
+        'point.lon': -77
       }
     };
     var res = {

test/unit/run.js

@@ -28,6 +28,7 @@ var tests = [
   require('./helper/types'),
   require('./sanitiser/_geo_common'),
   require('./middleware/distance'),
+  require('./middleware/confidenceScoreReverse'),
   require('./sanitiser/_size'),
 ];