Search Results

Search found 59554 results on 2383 pages for 'distributed data mining'.

Page 524/2383 | < Previous Page | 520 521 522 523 524 525 526 527 528 529 530 531  | Next Page >

  • Is frozenset adequate for caching of symmetric input data in a python dict?

    - by Debilski
    The title more or less says it all: I have a function which takes symmetric input in two arguments, e.g. something like def f(a1, a2): return heavy_stuff(abs(a1 - a2)) Now, I want to introduce some caching method. Would it be correct / pythonic / reasonably efficient to do something like this: cache = {} def g(a1, a2): return cache.setdefault(frozenset((tuple(a1), tuple(a2))), f(a1, a2)) Or would there be some better way?

    Read the article

  • Java: omitting a data member from the equals method.

    - by cchampion
    public class GamePiece { public GamePiece(char cLetter, int nPointValue) { m_cLetter=cLetter; m_nPointValue=nPointValue; m_nTurnPlaced=0; //has not been placed on game board yet. } public char GetLetter() {return m_cLetter;} public int GetPointValue() {return m_nPointValue;} public int GetTurnPlaced() {return m_nTurnPlaced;} public void SetTurnPlaced(int nTurnPlaced) { m_nTurnPlaced=nTurnPlaced; } @Override public boolean equals(Object obj) { /*NOTE to keep this shorter I omitted some of the null checking and instanceof stuff. */ GamePiece other = (GamePiece) obj; //not case sensitive, and I don`t think we want it to be here. if(m_cLetter != other.m_cLetter) { return false; } if(m_nPointValue != other.m_nPointValue) { return false; } /* NOTICE! m_nPointValue purposely omitted. It does not affect hashcode or equals */ return true; } @Override public int hashCode() { /* NOTICE! m_nPointValue purposely omitted. It should not affect hashcode or equals */ final int prime = 41; return prime * (prime + m_nPointValue + m_cLetter); } private char m_cLetter; private int m_nPointValue; private int m_nTurnPlaced;//turn which the game piece was placed on the game board. Does not affect equals or has code! } Consider the given piece of code. This object has been immutable until the introduction of the m_nTurnPlaced member (which can be modified by the SetTurnPlaced method, so now GamePiece becomes mutable). GamePiece is used in an ArrayList, I call contains and remove methods which both rely on the equals method to be implemented. My question is this, is it ok or common practice in Java for some members to not affect equals and hashcode? How will this affect its use in my ArrayList? What type of java Collections would it NOT be safe to use this object now that it is mutable? I've been told that you're not supposed to override equals on mutable objects because it causes some collections to behave "strangely" (I read that somewhere in the java documentation).

    Read the article

  • Sending data from one Protocol to another Protocol in Twisted?

    - by veb
    Hi! One of my protocols is connected to a server, and with the output of that I'd like to send it to the other protocol. I need to access the 'msg' method in ClassA from ClassB but I keep getting: exceptions.AttributeError: 'NoneType' object has no attribute 'write' Actual code: http://pastebin.com/MQPhduSY Any ideas please? :-)

    Read the article

  • SQL query for getting data in two fields from one column.

    - by AmiT
    I have a table [Tbl1] containing two fields. ID as int And TextValue as nvarchar(max) Suppose there are 7 records. I need a resultset that has two columns Text1 and Text2. The Text1 should have first 4 records and Text2 should have remaining 3 records. [Tbl1] ID | TextValue 1. | Apple 2. | Mango 3. | Orange 4. | Pineapple 5. | Banana 6. | Grapes 7. | Sapota Now, the result-set should have Text1 | Text2 Apple | Banana Mango | Grapes Orange | Sapota Pineapple |

    Read the article

  • Why does this data YYYY-MM-DD regex fail in Java?

    - by ProfessionalAmateur
    Hello StackOverFlow, My first question and Im excited... I've lurked since go-live and love the site, however I apologize for any newbie errors, formatting, etc... I'm attempting to validate the format of a string field that contains a date in Java. We will receive the date in a string, I will validate its format before parsing it into a real Date object. The format being passed in is in the YYYY-MM-DD format. However I'm stuck on one of my tests, if I pass in "1999-12-33" the test will fail (as it should with a day number 33) with this incomplete pattern: ((19|20)\\d{2})-([1-9]|0[1-9]|1[0-2])-([12][0-9]|3[01]) However as soon as I add the characters in bold below it passes the test (but should not) ((19|20)\\d{2})-([1-9]|0[1-9]|1[0-2])-(0[1-9]|[1-9]|[12][0-9]|3[01]) *additional note, I know I can change the 0[1-9]|[1-9] into 0?[1-9] but I wanted to break everything down to its most simple format to try and find why this isn't working. Here is the scrap test I've put together to run through all the different date scenarios: import java.util.regex.Matcher; import java.util.regex.Pattern; public class scrapTest { public scrapTest() { } public static void main(String[] args) { scrapTest a = new scrapTest(); boolean flag = a.verfiyDateFormat("1999-12-33"); } private boolean verfiyDateFormat(String dateStr){ Pattern datePattern = Pattern.compile("((19|20)\\d{2})-([1-9]|0[1-9]|1[0-2])-(0[1-9]|[1-9]|[12][0-9]|3[01])"); Matcher dateMatcher = datePattern.matcher(dateStr); if(!dateMatcher.find()){ System.out.println("Invalid date format!!! -> " + dateStr); return false; } System.out.println("Valid date format."); return true; } } Ive been programming for ~10 years but extremely new to Java, so please feel free to explain anything as elementary as you see fit.

    Read the article

  • Finding changes in MongoDB database

    - by Jonathan Knight
    I'm designing a MongoDB database that works with a script that periodically polls a resource and gets back a response which is stored in the database. Right now my database has one collection with four fields , id, name, timestamp and data. I need to be able to find out which names had changes in the data field between script runs, and which did not. In pseudocode, if(data[name][timestamp]==data[name][timestamp+1]) //data has not changed store data in collection 1 else //data has changed between script runs for this name store data in collection 2 Is there a query that can do this without iterating and running javascript over each item in the collection? There are millions of documents, so this would be pretty slow. Should I create a new collection named timestamp for every time the script runs? Would that make it faster/more organized? Is there a better schema that could be used? The script runs once a day so I won't run into a namespace limitation any time soon.

    Read the article

  • How do you read data from a ADODB stream in ASP as byte values?

    - by user89691
    I have an ASP routine that gets a binary file's contents and writes it to a stream. The intention is to read it from the stream and process it st the server. So I have: ResponseBody = SomeRequest (SomeURL) ; var BinaryInputStream = Server.CreateObject ("ADODB.Stream") ; BinaryInputStream.Type = 1 ; // binary BinaryInputStream.Open ; BinaryInputStream.Write (ResponseBody) ; BinaryInputStream.Position = 0 ; var DataByte = BinaryInputStream.Read (1) ; Response.Write (typeof (DataByte)) ; // displays "unknown" How do I get the byte value of the byte I have just read from the stream? Asc () and byte () don't work (JScript) TIA

    Read the article

  • Why can't I include these data files in a Python distribution using distutils?

    - by froadie
    I'm writing a setup.py file for a Python project so that I can distribute it. The aim is to eventually create a .egg file, but I'm trying to get it to work first with distutils and a regular .zip. This is an eclipse pydev project and my file structure is something like this: ProjectName src somePackage module1.py module2.py ... config propsFile1.ini propsFile2.ini propsFile3.ini setup.py Here's my setup.py code so far: from distutils.core import setup setup(name='ProjectName', version='1.0', packages=['somePackage'], data_files = [('config', ['..\config\propsFile1.ini', '..\config\propsFile2.ini', '..\config\propsFile3.ini'])] ) When I run this (with sdist as a command line parameter), a .zip file gets generated with all the python files - but the config files are not included. I thought that this code: data_files = [('config', ['..\config\propsFile1.ini', '..\config\propsFile2.ini', '..\config\propsFile3.ini'])] indicates that those 3 specified config files should be copied to a "config" directory in the zip distribution. Why is this code not accomplishing anything? What am I doing wrong? (I have also tried playing around with the paths of the config files... But nothing seems to help. Would Python throw an error or warning if the path was incorrect / file was not found?)

    Read the article

  • Is it possible to bind data asynchronously between two dropdownlists in a view?

    - by user252160
    I'd like to achieve the following effect using ASP.NET MVC and JQuery. I've got a drop down list displaying a list of Countries. I want to make it so that when I change the value of the country, a new drop down list appears below it, showing a list of companies whose country of origin is the particular selected company. The thing is that I do not want to rely too much on controller actions because I'm using it in a Template Helper which is a "headless" view. Can I bind it somehow?

    Read the article

  • How to access a control placed inside data template of listbox?

    - by Subhen
    Hi I have the following code: <ListBox x:Name="foldersListBox" Grid.Column="0" MouseLeftButtonUp="foldersListBox_MouseLeftButtonUp" BorderThickness="0" Height="AUTO" ScrollViewer.HorizontalScrollBarVisibility="Disabled" ScrollViewer.VerticalScrollBarVisibility="Disabled"> <DataTemplate> <Border BorderBrush="LightGray" BorderThickness="2" CornerRadius="4"> <Image x:Name="folderImage" Width="70" Height="70" Margin="3" /> </Border> </DataTemplate> </ListBox> Now when I am trying to access folderImage from code behind. I can use the loaded event and typecast the sender as Image type , but I dont want that way. Help plz. Thanks, Subhen

    Read the article

  • Updating a local sqlite db that is used for local metadata & caching from an service?

    - by Pharaun
    I've searched through the site and haven't found a question/answer that quite answer my question, the closest one I found was: Syncing objects between two disparate systems best approach. Anyway to begun, because there is no RSS feeds available, I'm screen scrapping a webpage, hence it does a fetch then it goes through the webpage to scrap out all of the information that I'm interested in and dumps that information into a sqlite database so that I can query the information at my leisure without doing repeat fetching from the website. However I'm also storing various metadata on the data itself that is stored in the sqlite db, such as: have I looked at the data, is the data new/old, bookmark to a chunk of data (Think of it as a collection of unrelated data, and the bookmark is just a pointer to where I am in processing/reading of the said data). So right now my current problem is trying to figure out how to update the local sqlite database with new data and/or changed data from the website in a manner that is effective and straightforward. Here's my current idea: Download the page itself Create a temporary table for the parsed data to go into Do a comparison between the official and the temporary table and copy updates and/or new information to the official table This process seems kind of complicated because I would have to figure out how to determine if the data in the temporary table is new, updated, or unchanged. So I am wondering if there isn't a better approach or if anyone has any suggestion on how to architecture/structure such system?

    Read the article

  • [PHP] building html tables from query data... faster?

    - by Andrew Heath
    With my limited experience/knowledge I am using the following structure to generate HTML tables on the fly from MySQL queries: $c = 0; $t = count($results); $table = '<table>'; while ($c < $t) { $table .= "<tr><td>$results[0]</td><td>$results[1]</td> (etc etc) </tr>"; ++$c; } $table .= '</table>'; this works, obviously. But for tables with 300+ rows there is a noticeable delay in pageload while the script builds the table. Currently the maximum results list is only about 1,100 rows, and the wait isn't long, but there's clearly a wait. Are there other methods for outputting an HTML table that are faster than my WHILE loop? (PHP only please...)

    Read the article

  • How to give default values for the sum, count if no data exist in mysql query which uses group by?

    - by Salil
    I am using following query which works fine for me except one problem SELECT f.period as month, sum(p.revenue * ((100-q.rate)/100)) as revenue ,count(distinct q.label) as tot_stmt FROM files f, reports p, rates q,albums a where f.period in ('2010-06-01','2010-05-01','2010-04-01','2010-03-01') and f.period_closed = true and q.period = f.period and a.id = q.album_id and p.file_id = f.id and p.upc = a.upc and p.revenue is not null GROUP BY month ORDER BY month DESC O/P = month            revenue     tot_stmt 2010-06-01     10.00         2 2010-05-01     340.47       2 I want result like following month            revenue     tot_stmt 2010-06-01     10.00         2 2010-05-01     340.47       2 2010-04-01     0.00           0 2010-03-01     0.00           0 Regards, Salil Gaikwad

    Read the article

  • Rails - Vestal Versions - Access previous version data w/o restoring?

    - by AnApprentice
    Hello, I'd like to use vestal versions to do the following: Determine the Content of the current record being saved Determine the Content of the last record saved In my model I have: class Note < ActiveRecord::Base versioned :if => :really_create_a_version? def really_create_a_version? XXXXXXXXXXXXXX XXXXXXXXXXXXXX end end Where the XXXX are, how can I get the note.content of the item about to be saved (i'm assuming it hasn't been saved yet to the DB? Is that correct? Also, how can I get the note.content of the save before the current save in progress? Thanks

    Read the article

  • How to programmatically fill a database

    - by Dwaine Bailey
    Hi There, I currently have an iPhone app that reads data from an external XML file at start-up, and then writes this data to the database (it only reads/writes data that the user's app has not seen before, though) My concern is that there is going to be a back catalogue of data of several years, and that the first time the user runs the app it will have to read this in and be atrociously slow. Our proposed solution is to include this data "pre-built" into the applications database, so that it doesn't have to load in the archival data on first-load - that is already in the app when they purchase it. My question is whether there is a way to automatically populate this data with data from, say, an XML file or something. The database is in SQLite. I would populate it by hand, but obviously this will take a very long time, so I was just wondering if anybody had a more...programmatic solution...

    Read the article

  • How can I remove sensitive data from the debug_backtrace function?

    - by RenderIn
    I am using print_r(debug_backtrace(), true) to retrieve a string representation of the debug backtrace. This works fine, as print_r handles recursion. When I tried to recursively iterate through the debug_backtrace() return array before turning it into a string it ran into recursion and never ended. Is there some simple way I can remove certain sensitive key/value pairs from the backtrace array? Perhaps some way to turn the array to a string using print_r, then back to an array with the recursive locations changed to the string RECURSION, which I could the iterate through. I don't want to execute regular expressions on the string representation if possible.

    Read the article

  • How to feed data over STDIN to multiple external commands in ruby.

    - by Erik
    This question is a bit like my previous (answered) question: How to run multiple external commands in the background in ruby. But, in this case I am looking for a way to feed ruby strings over STDIN to external processes, something like this (the code below is not valid but illustrates my goal): #!/usr/bin/ruby str1 = 'In reality a relatively large string.....' str2 = 'Another large string' str3 = 'etc..' spawn 'some_command.sh', :stdin => str1 spawn 'some_command.sh', :stdin => str2 spawn 'some_command.sh', :stdin => str3 Process.waitall

    Read the article

  • onselect in one combo it changes data dynamically in other combo?

    - by ajay
    Hello sir I am new to the jsp and ajax world. my problem is If i select one combo option then it should change the other combo options dynamically without submit button press. for example if i select the country then it should shows their states in other combo. I am using servlet & JSP and MS-ACCESS as backend. please reply as soon as possible. THANKING YOU....

    Read the article

  • How to update a table using a select group by in a second one as the data source in MySQL?

    - by Jader Dias
    I can't do this in MySQL UPDATE tableA, tableB SET tableA.column1 = SUM(tableB.column2) WHERE tableA.column3 = tableB.column4 GROUP BY tableB.column4 ; Neither can I UPDATE tableA, ( SELECT SUM(tableB.column2) sumB, tableB.column4 FROM tableB GROUP BY tableB.column4 ) t1 SET tableA.column1 = sumB WHERE tableA.column3 = column4 ; Besides it being illegal code, I think you can understand what I tried to do with the queries above. Both of them had the same intent. How can I do that in MySQL?

    Read the article

< Previous Page | 520 521 522 523 524 525 526 527 528 529 530 531  | Next Page >