/// <summary>
/// Get recommendations from a model
/// </summary>
/// <param name="modelId">The id of the model to recommend with</param>
/// <param name="usageEvents">Usage events to get recommendations for</param>
/// <param name="userId">An optional id of the user to provide recommendations for. Any stored usage events associated with this user will be considered when getting recommendations</param>
/// <param name="recommendationCount">Number of recommendations to get</param>
/// <param name="cancellationToken">A cancellation token used to abort the operation</param>
public async Task <IList <Recommendation> > ScoreAsync(Guid modelId, IEnumerable <IUsageEvent> usageEvents, string userId, int recommendationCount, CancellationToken cancellationToken)
{
// return empty result if no recommendations requested
if (recommendationCount <= 0)
{
Trace.TraceVerbose($"Requested '{recommendationCount}' recommendation for model '{modelId}' - returning empty recommendations.");
return(new Recommendation[0]);
}
Trace.TraceInformation($"Getting or creating a recommender for model '{modelId}'");
Recommender recommender = await GetOrCreateRecommenderAsync(modelId, cancellationToken);
try
{
Trace.TraceInformation($"Getting recommendations for model '{modelId}'");
return(recommender.GetRecommendations(usageEvents, userId, recommendationCount));
}
catch (Exception ex)
{
var exception = new Exception(
$"Exception while trying to get recommendations for model with id {modelId}", ex);
Trace.TraceError(exception.ToString());
throw exception;
}
}
// GET: Recommendations
public async Task <ActionResult> Index()
{
var userClaims = User.Identity as System.Security.Claims.ClaimsIdentity;
ViewBag.Name = userClaims?.FindFirst("name")?.Value;
IEnumerable <PreferenceEntity> preferenceEntities = TableActions.GetPreferencesResult("PreferenceTable", userClaims?.FindFirst(System.IdentityModel.Claims.ClaimTypes.Name)?.Value);
IEnumerable <PantryEntity> pantryEntities = TableActions.GetPantryResult("PantryTable", userClaims?.FindFirst(System.IdentityModel.Claims.ClaimTypes.Name)?.Value);
var preference = preferenceEntities.FirstOrDefault();
IEnumerable <string> dietaryRestrictions = null;
string diet = null;
if (preference != null)
{
dietaryRestrictions = preference.healthPreference.Split(',');
diet = preference.dietPreference;
}
string[] foods = { "pork", "bread", "peppers", "sugar", "corn" };
string[] pantryList = pantryEntities.Select(x => x.RowKey).ToArray();
IngredientList userPreferences = new IngredientList(foods);
IngredientList pantry = new IngredientList(pantryList);
List <Tuple <Recipe, double> > recs = await Recommender.GetRecommendations(userPreferences, pantry, dietaryRestrictions, diet);
return(View(recs));
}
public void GetRecommendationsUsingUserId()
{
const string baseFolder = nameof(GetRecommendationsUsingUserId);
Directory.CreateDirectory(baseFolder);
var generator = new ModelTrainingFilesGenerator(8);
string usageFileFolderPath = Path.Combine(baseFolder, "usage");
Directory.CreateDirectory(usageFileFolderPath);
IList <string> warmItems = generator.CreateUsageFile(Path.Combine(usageFileFolderPath, "usage.csv"), 1000);
var trainingParameters = ModelTrainingParameters.Default;
trainingParameters.EnableBackfilling = false;
trainingParameters.EnableUserToItemRecommendations = true;
trainingParameters.AllowSeedItemsInRecommendations = true;
Dictionary <string, Document> userHistory = null;
IDocumentStore documentStore = Substitute.For <IDocumentStore>();
documentStore.AddDocumentsAsync(Arg.Any <string>(), Arg.Any <IEnumerable <Document> >(),
Arg.Any <CancellationToken>())
.Returns(info =>
{
userHistory = info.Arg <IEnumerable <Document> >().ToDictionary(doc => doc.Id);
return(Task.FromResult(userHistory.Count));
});
documentStore.GetDocument(Arg.Any <string>(), Arg.Any <string>())
.Returns(info => userHistory?[info.ArgAt <string>(1)]);
var trainer = new ModelTrainer(documentStore: documentStore);
ModelTrainResult result = trainer.TrainModel(trainingParameters, usageFileFolderPath, null, null, CancellationToken.None);
Assert.IsNotNull(result);
Assert.IsTrue(result.IsCompletedSuccessfuly);
var recommender = new Recommender(result.Model, documentStore);
var items = new List <UsageEvent>
{
new UsageEvent
{
ItemId = warmItems.First(),
EventType = UsageEventType.Click,
Timestamp = DateTime.UtcNow
}
};
string userId = generator.Users.FirstOrDefault();
IList <Recommendation> recommendations = recommender.GetRecommendations(items, userId, 3);
// expect the document store to be called once with the provided user id
documentStore.Received(1).GetDocument(Arg.Any <string>(), userId);
Assert.IsNotNull(recommendations);
Assert.IsTrue(recommendations.Any());
Assert.IsTrue(recommendations.All(r => r != null));
Assert.IsTrue(recommendations.All(r => r.Score > 0 && !string.IsNullOrWhiteSpace(r.RecommendedItemId)));
}
public void GetRecommendationsUsingSmallModelWithDefaultParameters()
{
const string baseFolder = nameof(GetRecommendationsUsingSmallModelWithDefaultParameters);
Directory.CreateDirectory(baseFolder);
var generator = new ModelTrainingFilesGenerator(8);
string usageFileFolderPath = Path.Combine(baseFolder, "usage");
Directory.CreateDirectory(usageFileFolderPath);
IList <string> warmItems = generator.CreateUsageFile(Path.Combine(usageFileFolderPath, "usage.csv"), 1000);
var trainingParameters = ModelTrainingParameters.Default;
trainingParameters.EnableBackfilling = false;
var trainer = new ModelTrainer();
ModelTrainResult result = trainer.TrainModel(trainingParameters, usageFileFolderPath, null, null, CancellationToken.None);
Assert.IsNotNull(result);
Assert.IsTrue(result.IsCompletedSuccessfuly);
var recommender = new Recommender(result.Model);
var items = new List <UsageEvent>
{
new UsageEvent
{
ItemId = warmItems.First(),
EventType = UsageEventType.Click,
Timestamp = DateTime.UtcNow
}
};
IList <Recommendation> recommendations = recommender.GetRecommendations(items, null, 3);
Assert.IsNotNull(recommendations);
Assert.IsTrue(recommendations.Any());
Assert.IsTrue(recommendations.All(r => r != null));
Assert.IsTrue(recommendations.All(r => r.Score > 0 && !string.IsNullOrWhiteSpace(r.RecommendedItemId)));
}