FAQ Database Discussion Community


How does trec_eval calculates Mean Average Precision (MAP)?

search-engine,information-retrieval,data-retrieval
I'm using TREC_EVAL to evaluate a search engine. I'd like to know how it calculates the Mean Average Precision (MAP). I'm sure it doesn't calculate a simple average of the average precisions (AP). It seems a weighted arithmetic but I can't understand which weights are used.

Questions about CACM collection

search-engine,information-retrieval,data-retrieval
I'm using CACM document collection. I tried to search more information on this collection online but unfortunately I didn't find what I was looking for. If I've understood correctly, this collection contains documents from a paper journal. As far as this is concerned, I don't understand why every document always...

Count rows of data and display in view ASP.net MVC

sql,asp.net,asp.net-mvc,count,data-retrieval
All i'm trying to do is count how many bookings have requested wheelchair access not sure with the best way.... using (var context = new TalyllynContext()) { var count = context.Bookings.SqlQuery(" SELECT * FROM dbo.Booking Where Wheelchair_Access = 'true' ").Count(); } ViewBag.Count = count; This is what i want to...

What is the best way to retrieve table from MySQL using PHP?

php,mysql,stored-procedures,data-retrieval
I just have SELECT query which returns table. I don't like to type this query into PHP scripts. I want to create functions and procedures to retrieve data so I just call from PHP, and so it works properly with UPDATE, DELETE statements. But I can't return table! So what...

Unable to retrieve createdAt values from Parse objects

ios,uitableview,swift,parse.com,data-retrieval
I cannot get the createdAt value from Parse for each object.And I dont want to have to save an additional timestamp as a String when the data is sitting right there. This is the list of what i was doing.I hope someone who can help ---------------------------------------------------------------------- var followArray = [String]()...

How big a factor is blob size on retrieval time in Azure Storage?

azure-storage-blobs,data-retrieval
I am storing text files in Azure Blob Storage. The files will be on the order of 1MB, but I could theoretically reduce that size by perhaps 30% at the cost of significantly increasing my application logic complexity. I'm leaning toward just using the simpler but larger files. However, I...

Android parse value from .sqlite file

android,sqlite,data-retrieval
How to parse value from .sqlite file, i n my sqlite file there are more than 1000 records now i need to retrieve all the values and need to show that in a listview, i have saved that file in to my asset folder, is there any way to do...

How to retrieve data from sql by List<> instead of data table?

sql,database,list,data-recovery,data-retrieval
How to retrieve data from Database by ( List<> ) instead of data table? How can I do this?...

How to get a parameter as a result of a search condition from a XML-File? [duplicate]

java,web-services,parsing,data-retrieval,pattern-finding
This question already has an answer here: How to read XML using XPath in Java 4 answers Im getting via Webservice an XML File and now I want just to get certain data out of it by finding a certain match in the same tag: For example: < Person...