Search Results

Search found 13584 results on 544 pages for 'loading variables'.

Page 460/544 | < Previous Page | 456 457 458 459 460 461 462 463 464 465 466 467  | Next Page >

  • barebones sort algorithm

    - by user309322
    i have been asked to make a simple sort aglorithm to sort a random series of 6 numbers into numerical order. However i have been asked to do this using "Barebones" a theoretical language put forward in the Book Computer Science an overview. Some information on the language can be found here http://www.brouhaha.com/~eric/software/barebones/ Just to clarify i am a student teacher and have been doing anaysis on "mini-programing languages" and their uses in a teaching environment, i suggested to my tutor that i look at barebones and asked what sort of exmaple program i should write . He suggested a simple sort algorithm. Now since looking at the language i cant understand how i can do this without using arrays and if statements. The code to swap the value of variables would be while a not 0 do; incr Aux1; decr a; end; while b not 0 do; incr Aux2 decr b end; while Aux1 not 0 do; incr a; decr Aux1; end; while Aux2 not 0 do; incr b; decr Aux2; end; however the language does not provide < or operators

    Read the article

  • Numerical calculations in Prolog

    - by user8472
    While reading SICP I came across logic programming chapter 4.4. Then I started looking into the Prolog programming language and tried to understand some simple assignments in Prolog. I found that Prolog seems to have troubles with numerical calculations. Here is the computation of a factorial in standard Prolog: f(0, 1). f(A, B) :- A > 0, C is A-1, f(C, D), B is A*D. The issues I find is that I need to introduce two auxiliary variables (C and D), a new syntax (is) and that the problem is non-reversible (i.e., f(5,X) works as expected, but f(X,120) does not). Naively, I expect that at the very least C is A-1, f(C, D) above may be replaced by f(A-1,D), but even that does not work. My question is: Why do I need to do this extra "stuff" in numerical calculations but not in other queries? I do understand (and SICP is quite clear about it) that in general information on "what to do" is insufficient to answer the question of "how to do it". So the declarative knowledge in (at least some) math problems is insufficient to actually solve these problems. But that begs the next question: How does this extra "stuff" in Prolog help me to restrict the formulation to just those problems where "what to do" is sufficient to answer "how to do it"?

    Read the article

  • Significance in R

    - by Gemsie
    Ok, this is quite hard to explain, but I'm at a complete loss what to do. I'm a relative newcomer to R and although I can completely admire how powerful it is, I'm not too good at actually using it.... Basically, I have some very contrived data that I need to analyse (it wasn't me who chose this, I can assure you!). I have the right and left hand lengths of lots of people, as well as some numeric data that shows their sociability. Now I would like to know if people who have significantly different lengths of hand are more or less sociable than those who have the same (leading into the research that 'symmetrical' people are more sociable and intelligent, etc. I have got as far as loading the data into R, then I have no idea where to go from there. How on Earth do I start to separate those who are close to symmetrical to those who aren't to then start to do the analysis? Ok, using Sasha's great advice, I did the cor.test and got the following: Pearson's product-moment correlation data: measurements$l.hand - measurements$r.hand and measurements$sociable t = 0.2148, df = 150, p-value = 0.8302 alternative hypothesis: true correlation is not equal to 0 95 percent confidence interval: -0.1420623 0.1762437 sample estimates: cor 0.01753501 I have never used this test before, so am unsure how to intepret it...you wouldn't think I was on my fourth Scientific degree would you?! :(

    Read the article

  • receive and pass values with XML, AS3

    - by VideoDnd
    My example imports XML and has an object rotating on stage. The rotating object is called enemy corresponds to ENEMY in the XML. How do I set the rotation variable to receive values from XML? REASON It seems more difficult to set up variables using external data. I want to understand it better. here's a link http://videodnd.weebly.com/ rotation.fla //LOAD XML var myXML:XML; var myLoader:URLLoader = new URLLoader(); myLoader.load(new URLRequest("enemy.xml")); myLoader.addEventListener(Event.COMPLETE, processXML); //PARSE XML function processXML(e:Event):void { myXML = new XML(e.target.data); trace(myXML.ROGUE.*); trace(myXML); //TEXT var text:TextField = new TextField(); text.text = myXML.ENEMY.*; addChild(text); } //ROTATION function enterFrameHandler(event:Event):void { //==>CODE I WANT TO CHANGE<== enemy.rotationY += 10; //enemy.rotationY = myXML.ENEMY.*; } addEventListener(Event.ENTER_FRAME, enterFrameHandler); enemy.xml ENEMY is set to -100, use what you like <?xml version="1.0" encoding="utf-8"?> <BADGUYS> <ENEMY TITLE="sticky">-100</ENEMY> <ROGUE TITLE="slimy">-1000</ROGUE> </BADGUYS>

    Read the article

  • AppDomain.Unload doesn't release the assembly I loaded up with Reflection

    Hi All, I am struggling with an issue while loading an assembly up in a temporary AppDomain to read its GetUsedReferences property. Once I do that, I call AppDomain.Unload(tempDomain) and then I try to clean up my mess by deleting the files. That fails because the file is locked. I Unloaded the temporary domain though! Any thoughts or suggestions would be greately appreciated. Here is some of my code: //I already have btyes for the .dll and the .pdb from the actual files AppDomainSetup domainSetup = new AppDomainSetup(); domainSetup.ApplicationBase = Environment.CurrentDirectory; domainSetup.ShadowCopyFiles = "true"; domainSetup.CachePath = Environment.CurrentDirectory; AppDomain tempAppDomain = AppDomain.CreateDomain("TempAppDomain", AppDomain.CurrentDomain.Evidence, domainSetup); //Load up the temp assembly and do stuff Assembly projectAssembly = tempAppDomain.Load(assemblyFileBuffer, symbolsFileBuffer); //Then I'm trying to clean up AppDomain.Unload(tempAppDomain); tempAppDomain = null; File.Delete(tempAssemblyFile); //I even try to force GC File.Delete(tempSymbolsFile); Anyway, the Deletes fail because the files are locked still. Shouldn't they be released because I Unloaded the temporary AppDomain?!?!?! Thanks in advance, Dan

    Read the article

  • Java: Embedding Soundbank file in JAR

    - by Pyroclastic
    If I have a soundbank stored in a JAR, how would I load that soundbank into my application using resource loading...? I'm trying to consolidate as much of a MIDI program into the jar file as I can, and the last thing I have to add is the soundbank file I'm using, as users won't have the soundbanks installed. I'm trying to put it into my jar file, and then load it with getResource() in the Class class, but I'm getting an InvalidMidiDataException on a soundbank that I know is valid. Here's the code, it's in the constructor for my synthesizer object: try { synth = MidiSystem.getSynthesizer(); channels = synth.getChannels(); instrument = MidiSystem.getSoundbank(this.getClass().getResource("img/soundbank-mid.gm")).getInstruments(); currentInstrument = instrument[0]; synth.loadInstrument(currentInstrument); synth.open(); } catch (InvalidMidiDataException ex) { System.out.println("FAIL"); instrument = synth.getAvailableInstruments(); currentInstrument = instrument[0]; synth.loadInstrument(currentInstrument); try { synth.open(); } catch (MidiUnavailableException ex1) { Logger.getLogger(MIDISynth.class.getName()).log(Level.SEVERE, null, ex1); } } catch (IOException ex) { Logger.getLogger(MIDISynth.class.getName()).log(Level.SEVERE, null, ex); } catch (MidiUnavailableException ex) { Logger.getLogger(MIDISynth.class.getName()).log(Level.SEVERE, null, ex); }

    Read the article

  • C# Cast Class to Overridden Class

    - by Nathan Tornquist
    I have a class Application that I need to override with INotifyPropertyChanged events. I have written the logic to override the original class and ended up creating SuperApplication I am pulling the data from a library though, and cannot change the loading logic. I just need a way to get the data from the original class into my superClass. I've tried things like superClass = (SuperApplication)standardClass; but it hasn't worked. How would I go about doing this? If it helps, this is the code I'm using to override the original class: public class SuperCreditApplication : CreditApplication { public SuperCreditApplicant Applicant { get; set; } public SuperCreditApplicant CoApplicant { get; set; } } public class SuperCreditApplicant : CreditApplicant { public SuperProspect Prospect { get; set; } } public class SuperProspect : Prospect, INotifyPropertyChanged { public State DriverLicenseState { get { return DriverLicenseState; } set { DriverLicenseState = value; OnPropertyChanged("DriverLicenseState"); } } public event PropertyChangedEventHandler PropertyChanged; private void OnPropertyChanged(string propertyName) { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } }

    Read the article

  • Database structure for ecommerce site

    - by imanc
    Hey Guys, I have been tasked with designing an ecommerce solution. The aspect that is causing me the most problems is the database. Currently the site consists of 10+ country based shops each with their own database (all residing on the same mysql instance). For the new site I'd rather all these shop databases be merged into one database so that all tables (products, orders, customers etc.) have a shop_id field. From a programming perspective this seems to make the most sense as we won't have to manage data across multiple databases. Currently the entire site generates about 120k orders a year, but is experiencing fairly heavy growth and we need to design a solution that will scale. In 5 years there may be more than a million orders per year and a database that contains 5 years order history (archiving maybe a solution here). The question is - do we use a single database, or do we keep the database-per-shop structure? I am currently trying to find supporting evidence for either avenue. The company I am designing the solution for prefer the per-shop database structure because they believe it will allow the sites to scale. But my argument is that the shop's database probably won't get that busy over the next few years that they exceed the capacity of a mysql database and a "no expenses spared" hardware set-up. I am wondering if anyone has any advice either way? Does anyone have experience with websites / ecommerce sites that have tables containing millions of records? I know there is probably not a clear answer here, but at what stage do we have too many records or too large table files to have a fast loading site? Also, if anyone has any advice on sources of information - books, websites, etc. where I can do further research, it would be highly appreciated! Cheers, imanc

    Read the article

  • mod_rewrite to redirect URL with query string

    - by meeble
    I've searched all over stackoverflow, but none of the answers seem to be working for this situation. I have a lot of working mod_rewrite rules already in my httpd.conf file. I just recently found that Google had indexed one of my non-rewritten URLs with a query string in it: http://domain.com/?state=arizona I would like to use mod_rewrite to do a 301 redirect to this URL: http://domain.com/arizona The issue is that later on in my rewrite rules, that 2nd URL is being rewritten to pass query variables on to WordPress. It ends up getting rewritten to: http://domain.com/index.php?state=arizona Which is the proper functionality. Everything I have tried so far has either not worked at all or put me in an endless rewrite loop. This is what I have right now, which is getting stuck in a loop: RewriteCond %{QUERY_STRING} state=arizona [NC] RewriteRule .* http://domain.com/arizona [R=301,L] #older rewrite rule that passes query string based on URL: RewriteRule ^([A-Za-z-]+)$ index.php?state=$1 [L] which gives me an endless rewrite loop and takes me to this URL: http://domain.com/arizona?state=arizona I then tried this: RewriteRule .* http://domain.com/arizona? [R=301,L] which got rid of the query string in the URL, but still creates a loop.

    Read the article

  • SQL wont work? It doesn't come up with errors either

    - by Stefan
    Hey there, I have php function which checks to see if variables are set and then adds them onto my sql query. However I am don't seem to be getting any results back!? $where_array = array(); if (array_key_exists("location", $_GET)) { $location = addslashes($_GET['location']); $where_array[] = "`mainID` = '".$location."'"; } if (array_key_exists("gender", $_GET)) { $gender = addslashes($_GET["gender"]); $where_array[] = "`gender` = '".$gender."'"; } if (array_key_exists("hair", $_GET)) { $hair = addslashes($_GET["hair"]); $where_array[] = "`hair` = '".$hair."'"; } if (array_key_exists("area", $_GET)) { $area = addslashes($_GET["area"]); $where_array[] = "`locationID` = '".$area."'"; } $where_expr = ''; if ($where_array) { $where_expr = "WHERE " . implode(" AND ", $where_array); } $sql = "SELECT `postID` FROM `posts` ". $where_expr; $dbi = new db(); $result = $dbi->query($sql); $r = mysql_fetch_row($result); I'm trying to call the data after in a list like so: $dbi = new db(); $offset = ($currentpage - 1) * $rowsperpage; // get the info from the db $sql .= " ORDER BY `time` DESC LIMIT $offset, $rowsperpage"; $result = $dbi->query($sql); // while there are rows to be fetched... while ($row = mysql_fetch_object($result)){ // echo data echo $row['text']; } // end while Anyone got any ideas why I am not retrieving any data? -Stefan

    Read the article

  • What is the fastest way to do division in C for 8bit MCUs?

    - by Jordan S
    I am working on the firmware for a device that uses an 8bit mcu (8051 architecture). I am using SDCC (Small Device C Compiler). I have a function that I use to set the speed of a stepper motor that my circuit is driving. The speed is set by loading a desired value into the reload register for a timer. I have a variable, MotorSpeed that is in the range of 0 to 1200 which represents pulses per second to the motor. My function to convert MotorSpeed to the correct 16bit reload value is shown below. I know that float point operations are pretty slow and I am wondering if there is a faster way of doing this... void SetSpeed() { float t = MotorSpeed; unsigned int j = 0; t = 1/t ; t = t / 0.000001; j = MaxInt - t; TMR3RL = j; // Set reload register for desired freq return; }

    Read the article

  • Problem executing trackPageview with Google Analytics.

    - by dmrnj
    I'm trying to capture the clicks of certain download links and track them in Google Analytics. Here's my code var links = document.getElementsByTagName("a"); for (var i = 0; i < links.length; i++) { linkpath = links[i].pathname; if( linkpath.match(/\.(pdf|xls|ppt|doc|zip|txt)$/) || links[i].href.indexOf("mode=pdf") >=0 ){ //this matches our search addClickTracker(links[i]); } } function addClickTracker(obj){ if (obj.addEventListener) { obj.addEventListener('click', track , true); } else if (obj.attachEvent) { obj.attachEvent("on" + 'click', track); } } function track(e){ linkhref = (e.srcElement) ? e.srcElement.pathname : this.pathname; pageTracker._trackPageview(linkhref); } Everything up until the pageTracker._trackPageview() call works. In my debugging linkhref is being passed fine as a string. No abnormal characters, nothing. The issue is that, watching my http requests, Google never makes a second call to the tracking gif (as it does if you call this function in an "onclick" property). Calling the tracker from my JS console also works as expected. It's only in my listener. Could it be that my listener is not deferring the default action (loading the new page) before it has a chance to contact Google's servers? I've seen other tracking scripts that do a similar thing without any deferral.

    Read the article

  • Tablesorter Pager not working in Safari or Chrome

    - by Zendog74
    Hi all. I am building an app using the tablesorter plug-in and it's pager plug-in. Things work perfectly fine in Firefox and IE, but in Safari (4.0.4 on a PC) and Chrome () I get errors when it hits the following code that binds the tablesorter pager. I took the pager binding out and it worked, so something is going wrong somewhere in those three lines of code. var tableSel = calendarportlet.ut.createIdSelector(calendarportlet.addNamespace("eventListTable")); var pagerSel = calendarportlet.ut.createIdSelector(calendarportlet.addNamespace("pager")); jQuery(tableSel).tablesorter({ widthFixed: true, headers: { 0: {sorter: false} }, sortList:[[2,1],[1,0]], widgets: ['zebra'] }).tablesorterPager({ <-- error happens in here container: jQuery(pagerSel), positionFixed: false }); Also, the errors only happen in Safari and Chrome when prototype.js is loaded AFTER jQuery. If they are loaded before jQuery, it works fine. However, this is a portlet and it has to play nice with other portlets, so we don't want to modify the header and loading order of the js libs. Anyone have any ideas on how to fix this?

    Read the article

  • A C# Refactoring Question...

    - by james lewis
    I came accross the following code today and I didn't like it. It's fairly obvious what it's doing but I'll add a little explanation here anyway: Basically it reads all the settings for an app from the DB and the iterates through all of them looking for the DB Version and the APP Version then sets some variables to the values in the DB (to be used later). I looked at it and thought it was a bit ugly - I don't like switch statements and I hate things that carry on iterating through a list once they're finished. So I decided to refactor it. My question to all of you is how would you refactor it? Or do you think it even needs refactoring at all? Here's the code: using (var sqlConnection = new SqlConnection(Lfepa.Itrs.Framework.Configuration.ConnectionString)) { sqlConnection.Open(); var dataTable = new DataTable("Settings"); var selectCommand = new SqlCommand(Lfepa.Itrs.Data.Database.Commands.dbo.SettingsSelAll, sqlConnection); var reader = selectCommand.ExecuteReader(); while (reader.Read()) { switch (reader[SettingKeyColumnName].ToString().ToUpper()) { case DatabaseVersionKey: DatabaseVersion = new Version(reader[SettingValueColumneName].ToString()); break; case ApplicationVersionKey: ApplicationVersion = new Version(reader[SettingValueColumneName].ToString()); break; default: break; } } if (DatabaseVersion == null) throw new ApplicationException("Colud not load Database Version Setting from the database."); if (ApplicationVersion == null) throw new ApplicationException("Colud not load Application Version Setting from the database."); }

    Read the article

  • Ember Data Sycn - LocalStorage+REST+RealTime+Online/Offline

    - by Miguel Madero
    We have a combination of requirements in terms o data access. Pre-load some reference data. We need reference data to survive browser restarts instead of just living in memory to avoid loading it all the time. I'm currently using the LocalStorageAdapter for that. Once we have it, we would like to sync changes (polling or using Socket.IO in the background and updating the LocalStorage could do the trick) There're other models that are more transactional, where we would need to directly go to the Server and get/save them. It would be nice to use something like the RESTAdapter for that. Lastly, there're some operations that should work off-line and changes should be synced later. To make it more concrete: * We pre-load vendor and "favorite products" into Local Storage. We work offline with those. * We need to sync server changes to vendor and product information. * If they search the full catalog, that requires them to be online. * When offline, we need to allow users to add something to their cart or even submit and order. We would like to queue this action and submit it when they have an Internet Connection. So a few questions are derived from this: * Is there a way to user RESTAdapter in combination with LocalStorage? * Is there some Socket.IO support? (Happy to do this part manually) * Is there Queueing support? Ideally at the Ember-Data level. I know we will have to do a lot of this manually and pull together the different lego pieces, but I wanted to ask for some perspective from experience Ember devs.

    Read the article

  • SSRS code variable resetting on new page

    - by edmicman
    In SSRS 2008 I am trying to maintain a SUM of SUMs on a group using custom Code. The reason is that I have a table of data, grouped and returning SUMs of the data. I have a filter on the group to remove lines where group sums are zero. Everything works except I'm running into problems with the group totals - it should be summing the visible group totals but is instead summing the entire dataset. There's tons of articles about how to work around this, usually using custom code. I've made custom functions and variables to maintain a counter: Public Dim GroupMedTotal as Integer Public Dim GrandMedTotal as Integer Public Function CalcMedTotal(ThisValue as Integer) as Integer GroupMedTotal = GroupMedTotal + ThisValue GrandMedTotal = GrandMedTotal + ThisValue Return ThisValue End Function Public Function ReturnMedSubtotal() as Integer Dim ThisValue as Integer = GroupMedTotal GroupMedTotal = 0 Return ThisValue End Function Basically CalcMedTotal is fed a SUM of a group, and maintains a running total of that sum. Then in the group total line I output ReturnMedSubtotal which is supposed to give me the accumulated total and reset it for the next group. This actually works great, EXCEPT - it is resetting the GroupMedTotal value on each page break. I don't have page breaks explicitly set, it's just the natural break in the SSRS viewer. And if I export the results to Excel everything works and looks correctly. If I output Code.GroupMedTotal on each group row, I see it count correctly, and then if a group spans multiple pages on the next page GroupMedTotal is reset and begins counting from zero again. Any help in what's going on or how to work around this? Thanks!

    Read the article

  • How to cancel a jquery.load()?

    - by Dirk Jönsson
    I'd like to cancel a .load() operation, when the load() does not return in 5 seconds. If it's so I show an error message like 'sorry, no picture loaded'. What I have is... ...the timeout handling: jQuery.fn.idle = function(time, postFunction){ var i = $(this); i.queue(function(){ setTimeout(function(){ i.dequeue(); postFunction(); }, time); }); return $(this); }; ... initializing of the error message timeout: var hasImage = false; $('#errorMessage') .idle(5000, function() { if(!hasImage) { // 1. cancel .load() // 2. show error message } }); ... the image loading: $('#myImage') .attr('src', '/url/anypath/image.png') .load(function(){ hasImage = true; // do something... }); The only thing I could not figure out is how to cancel the running load() (if it's possible). Please help. Thanks! Edit: Another way: How do I prevent the .load() method to call it's callback function when it's returning?

    Read the article

  • Create static instances of a class inside said class in Python

    - by Samir Talwar
    Apologies if I've got the terminology wrong here—I can't think what this particular idiom would be called. I've been trying to create a Python 3 class that statically declares instances of itself inside itself—sort of like an enum would work. Here's a simplified version of the code I wrote: class Test: A = Test("A") B = Test("B") def __init__(self, value): self.value = value def __str__(self): return "Test: " + self.value print(str(Test.A)) print(str(Test.B)) Writing this, I got an exception on line 2 (A = Test("A")). I assume line 3 would also error if it had made it that far. Using __class__ instead of Test gives the same error. File "<stdin>", line 1, in <module> File "<stdin>", line 2, in Test NameError: name 'Test' is not defined Is there any way to refer to the current class in a static context in Python? I could declare these particular variables outside the class or in a separate class, but for clarity's sake, I'd rather not if I can help it. To better demonstrate what I'm trying to do, here's the same example in Java: public class Test { private static final Test A = new Test("A"); private static final Test B = new Test("B"); private final String value; public Test(String value) { this.value = value; } public String toString() { return "Test: " + value; } public static void main(String[] args) { System.out.println(A); System.out.println(B); } } This works as you would expect: it prints: Test: A Test: B How can I do the same thing in Python?

    Read the article

  • PHP, MySQL prepared statements - can you use results of execute more than once by calling data_seek(

    - by Carvell Fenton
    Hello, I have a case where I want to use the results of a prepared statement more than once in a nested loop. The outer loop processes the results of another query, and the inner loop is the results of the prepared statement query. So the code would be something like this (just "pseudoish" to demonstrate the concept): // not showing the outer query, it is just a basic SELECT, not prepared statement // we'll call it $outer_query $obj_array = array(); // going to save objects in this $ids = array(18,19,20); // just example id numbers $query = "SELECT field1, field2 FROM table1 WHERE id=?"; $stmt = $db->prepare($query); foreach ($ids as $id) { $stmt->bind_param("i", $id); $stmt->execute(); $stmt->bind_result($var1, $var2); $stmt->store_result(); // I think I need this for data_seek while ($q1 = $outer_query->fetch_object()) { while ($stmt->fetch()) { if ($q1->field1 == $var1) { // looking for a match $obj = new stdClass(); $obj->var1 = $var1; $obj->var2 = $var2; $obj_array[] = $obj; $stmt->data_seek(0); // reset for outer loop break; // found match, so leave inner } } } } The problem I seem to be experiencing is that the values are not getting bound in the variables as I would expect after the first time I use fetch in the inner loop. Specifically, in one example I ran with 3 ids for the foreach, the first id was processed correctly, the second was processed incorrectly (matches were not found in the inner loop even though they existed), and then the third was processed correctly. Is there something wrong with the prepared statment function calls in the sequence I am doing above, or is this an invalid way to use the results of the prepared statement? Thanks.

    Read the article

  • R: Are there any alternatives to loops for subsetting from an optimization standpoint?

    - by Adam
    A recurring analysis paradigm I encounter in my research is the need to subset based on all different group id values, performing statistical analysis on each group in turn, and putting the results in an output matrix for further processing/summarizing. How I typically do this in R is something like the following: data.mat <- read.csv("...") groupids <- unique(data.mat$ID) #Assume there are then 100 unique groups results <- matrix(rep("NA",300),ncol=3,nrow=100) for(i in 1:100) { tempmat <- subset(data.mat,ID==groupids[i]) #Run various stats on tempmat (correlations, regressions, etc), checking to #make sure this specific group doesn't have NAs in the variables I'm using #and assign results to x, y, and z, for example. results[i,1] <- x results[i,2] <- y results[i,3] <- z } This ends up working for me, but depending on the size of the data and the number of groups I'm working with, this can take up to three days. Besides branching out into parallel processing, is there any "trick" for making something like this run faster? For instance, converting the loops into something else (something like an apply with a function containing the stats I want to run inside the loop), or eliminating the need to actually assign the subset of data to a variable?

    Read the article

  • How do I build a filtered_streambuf based on basic_streambuf?

    - by swestrup
    I have a project that requires me to insert a filter into a stream so that outgoing data will be modified according to the filter. After some research, it seems that what I want to do is create a filtered_streambuf like this: template <class StreamBuf class filtered_streambuf: public StreamBuf { ... } And then insert a filtered_streambuf<> into whichever stream I need to be filtered. My problem is that I don't know what invariants I need to maintain while filtering a stream, in order to ensure that Derived classes can work as expected. In particular, I may find I have filtered_streambufs built over other filtered_streambufs. All the various stream inserters, extractors and manipulators work as expected. The trouble is that I just can't seem to work out what the minimal interface is that I need to supply in order to guarantee that an iostream will have what it needs to work correctly. In particular, do I need to fake the movement of the protected pointer variables, or not? Do I need a fake data buffer, or not? Can I just override the public functions, rewriting them in terms of the base streambuf, or is that too simplistic?

    Read the article

  • reshaping a data frame into long format in R

    - by user1773115
    I'm struggling with a reshape in R. I have 2 types of error (err and rel_err) that have been calculated for 3 different models. This gives me a total of 6 error variables (i.e. err_1, err_2, err_3, rel_err_1, rel_err_2, and rel_err_3). For each of these types of error I have 3 different types of predivtive validity tests (ie random holdouts, backcast, forecast). I would like to make my data set long so I keep the 4 types of test long while also making the two error measurements long. So in the end I will have one variable called err and one called rel_err as well as an id variable for what model the error corresponds to (1,2,or 3) Here is my data right now: iter err_1 rel_err_1 err_2 rel_err_2 err_3 rel_err_3 test_type 1 -0.09385732 -0.2235443 -0.1216982 -0.2898543 -0.1058366 -0.2520759 random 1 0.16141630 0.8575728 0.1418732 0.7537442 0.1584816 0.8419816 back 1 0.16376930 0.8700738 0.1431505 0.7605302 0.1596502 0.8481901 front 1 0.14345986 0.6765194 0.1213689 0.5723444 0.1374676 0.6482615 random 1 0.15890059 0.7435382 0.1589823 0.7439204 0.1608709 0.7527580 back 1 0.14412360 0.6743928 0.1442039 0.6747684 0.1463520 0.6848202 front and here is what I would like it to look like: iter model err rel_err test_type 1 1 -0.09385732 (#'s) random 1 2 -0.1216982 (#'s) random 1 3 -0.1216982 (#'s) random and on... I've tried playing around with the syntax but can't quite figure out what to put for the time.varying argument Thanks very much for any help you can offer.

    Read the article

  • How to store and remove dynamically and automatic variable of generic data type in custum list data

    - by Vineel Kumar Reddy
    Hi I have created a List data structure implementation for generic data type with each node declared as following. struct Node { void *data; .... .... } So each node in my list will have pointer to the actual data(generic could be anything) item that should be stored in the list. I have following signature for adding a node to the list AddNode(struct List *list, void* eledata); the problem is when i want to remove a node i want to free even the data block pointed by *data pointer inside the node structure that is going to be freed. at first freeing of datablock seems to be straight forward free(data) // forget about the syntax..... But if data is pointing to a block created by malloc then the above call is fine....and we can free that block using free function int *x = (int*) malloc(sizeof(int)); *x = 10; AddNode(list,(void*)x); // x can be freed as it was created using malloc what if a node is created as following int x = 10; AddNode(list,(void*)&x); // x cannot be freed as it was not created using malloc Here we cannot call free on variable x!!!! How do i know or implement the functionality for both dynamically allocated variables and static ones....that are passed to my list.... Thanks in advance...

    Read the article

  • Converting contents of a byte array to wchar_t*

    - by Christopher MacKinnon
    I seem to be having an issue converting a byte array (containing the text from a word document) to a LPTSTR (wchar_t *) object. Every time the code executes, I am getting a bunch of unwanted Unicode characters returned. I figure it is because I am not making the proper calls somewhere, or not using the variables properly, but not quite sure how to approach this. Hopefully someone here can guide me in the right direction. The first thing that happens in we call into C# code to open up Microsoft Word and convert the text in the document into a byte array. byte document __gc[]; document = word->ConvertToArray(filename); The contents of document are as follows: {84, 101, 115, 116, 32, 68, 111, 99, 117, 109, 101, 110, 116, 13, 10} Which ends up being the following string: "Test Document". Our next step is to allocate the memory to store the byte array into a LPTSTR variable, byte __pin * value; value = &document[0]; LPTSTR image; image = (LPTSTR)malloc( document->Length + 1 ); Once we execute the line where we start allocating the memory, our image variable gets filled with a bunch of unwanted Unicode characters: ????????????????? And then we do a memcpy to transfer over all of the data memcpy(image,value,document->Length); Which just causes more unwanted Unicode characters to appear: ????????????????? I figure the issue that we are having is either related to how we are storing the values in the byte array, or possibly when we are copying the data from the byte array to the LPTSTR variable. Any help with explaining what I'm doing wrong, or anything to point me in the right direction will be greatly appreciated.

    Read the article

  • Packing an exe + dll into one executable (not .NET)

    - by Bluebird75
    Hi, Is anybody aware of a program that can pack several DLL and a .EXE into one executable. I am not talking about .NET case here, I am talking about general DLLs, some of which I generate in C++, some of others are external DLL I have no control over. My specific case is a python program packaged with py2exe, where I would like to "hide" the other DLL by packing them. The question is general enough though. The things that had a look at: ILMerge: specific to .NET NETZ: specific to .NET UPX: does DLL compression but not multiple DLL + EXE packing FileJoiner: Almost got it. It can pack executable + anything into one exe but when opened, it will launch the default opener for every file that was packed. So, if the user user dlldepend installed, it will launch it (becaues that's the default dll opener). Maybe that's not possible ? Summary of the answers: DLL opening is managed by the OS, so packing DLL into executable means that at some point, they need to be extracted to a place where the OS can find them. No magic bullet. So, what I want is not possible. Unless... We change something in the OS. Thanks Conrad for pointing me to ThinInstall, which virtualise the application and the OS loading mechanism. With ThinInstall, it is possible to pack everything in one exe (DLL, registry settings, ...).

    Read the article

< Previous Page | 456 457 458 459 460 461 462 463 464 465 466 467  | Next Page >