Search Results

Search found 59975 results on 2399 pages for 'data comparison'.

Page 727/2399 | < Previous Page | 723 724 725 726 727 728 729 730 731 732 733 734  | Next Page >

• Using an embedded DB (SQLite / SQL Compact) for Message Passing within an app?

  - by wk1989

  Hello, Just out of curiosity, for applications that have a fairly complicated module tree, would something like sqlite/sql compact edition work well for message passing? So if I have modules containing data such as: \SubsystemA\SubSubSysB\ModuleB\ModuleDataC, \SubSystemB\SubSubSystemC\ModuleA\ModuleDataX Using traditional message passing/routing, you have to go through intermediate modules in order to pass a message to ModuleB to request say ModuleDataC. Instead of doing that, if we we simply store "\SubsystemA\SubSubSysB\ModuleB\ModuleDataC" in a sqlite database, getting that data is as simple as a sql query and needs no routing and passing stuff around. Has anyone done this before? Even if you haven't, do you foresee any issues & performance impact? The only concern I have right now would be the passing of custom types, e.g. if ModuleDataC is a custom data structure or a pointer, I'll need some way of storing the data structure into the DB or storing the pointer into the DB. Thanks, JW EDIT One usage case I haven't thought about is when you want to send a message from ModuleA to ModuleB to get ModuleB to do something rather than just getting/setting data. Is it possible to do this using an embedded DB? I believe callback from the DB would be needed, how feasible is this?

  Read the article

• Do superfluous calls to addEventListenter("event", thisSpecificFunction) waste resources?

  - by Richard Haven

  I have ItemRenderers that need to listen for events. When they hear an event (and when data changes), they dispatch an event with their current data value. As item renderers are reused, each of them is going to add its callback in set data(value...)and pass the callback function in the event as well as the current data value. So, the listener of the item renderer's bubbling event will set someEventDispatcher.addEventListener("someEvent", itemRendererEvent.callbackListener). This will happen more than once. Does setting the same event listener on the same event for the same dispatcher waste resources? Does the displatcher see that it already has the listener?

  Read the article

• highlight text in 2 textboxes at the same time

  - by user1907736

  I am trying to create a packet analyzer for an online game using C# and I am new to c#. I have 2 RichTextBoxes, 1 shows the packet in bytes and the other one shows the packet in ANSI. Here is what I want to achieve: When I select(highlight) data in the byte text box, I want the corresponding data in the ANSI text box to also be highlighted. (and vice-versa) When I change data in the 1 of the textboxes, I want the corresponding data in the other textbox to also be changed. How do I do these?

  Read the article

• Does my basic PHP Socket Server need optimization?

  - by Tom

  Like many people, I can do a lot of things with PHP. One problem I do face constantly is that other people can do it much cleaner, much more organized and much more structured. This also results in much faster execution times and much less bugs. I just finished writing a basic PHP Socket Server (the real core), and am asking you if you can tell me what I should do different before I start expanding the core. I'm not asking about improvements such as encrypted data, authentication or multi-threading. I'm more wondering about questions like "should I maybe do it in a more object oriented way (using PHP5)?", or "is the general structure of the way the script works good, or should some things be done different?". Basically, "is this how the core of a socket server should work?" In fact, I think that if I just show you the code here many of you will immediately see room for improvements. Please be so kind to tell me. Thanks! #!/usr/bin/php -q <? // config $timelimit = 180; // amount of seconds the server should run for, 0 = run indefintely $address = $_SERVER['SERVER_ADDR']; // the server's external IP $port = 9000; // the port to listen on $backlog = SOMAXCONN; // the maximum of backlog incoming connections that will be queued for processing // configure custom PHP settings error_reporting(1); // report all errors ini_set('display_errors', 1); // display all errors set_time_limit($timelimit); // timeout after x seconds ob_implicit_flush(); // results in a flush operation after every output call //create master IPv4 based TCP socket if (!($master = socket_create(AF_INET, SOCK_STREAM, SOL_TCP))) die("Could not create master socket, error: ".socket_strerror(socket_last_error())); // set socket options (local addresses can be reused) if (!socket_set_option($master, SOL_SOCKET, SO_REUSEADDR, 1)) die("Could not set socket options, error: ".socket_strerror(socket_last_error())); // bind to socket server if (!socket_bind($master, $address, $port)) die("Could not bind to socket server, error: ".socket_strerror(socket_last_error())); // start listening if (!socket_listen($master, $backlog)) die("Could not start listening to socket, error: ".socket_strerror(socket_last_error())); //display startup information echo "[".date('Y-m-d H:i:s')."] SERVER CREATED (MAXCONN: ".SOMAXCONN.").\n"; //max connections is a kernel variable and can be adjusted with sysctl echo "[".date('Y-m-d H:i:s')."] Listening on ".$address.":".$port.".\n"; $time = time(); //set startup timestamp // init read sockets array $read_sockets = array($master); // continuously handle incoming socket messages, or close if time limit has been reached while ((!$timelimit) or (time() - $time < $timelimit)) { $changed_sockets = $read_sockets; socket_select($changed_sockets, $write = null, $except = null, null); foreach($changed_sockets as $socket) { if ($socket == $master) { if (($client = socket_accept($master)) < 0) { echo "[".date('Y-m-d H:i:s')."] Socket_accept() failed, error: ".socket_strerror(socket_last_error())."\n"; continue; } else { array_push($read_sockets, $client); echo "[".date('Y-m-d H:i:s')."] Client #".count($read_sockets)." connected (connections: ".count($read_sockets)."/".SOMAXCONN.")\n"; } } else { $data = @socket_read($socket, 1024, PHP_NORMAL_READ); //read a maximum of 1024 bytes until a new line has been sent if ($data === false) { //the client disconnected $index = array_search($socket, $read_sockets); unset($read_sockets[$index]); socket_close($socket); echo "[".date('Y-m-d H:i:s')."] Client #".($index-1)." disconnected (connections: ".count($read_sockets)."/".SOMAXCONN.")\n"; } else { if ($data = trim($data)) { //remove whitespace and continue only if the message is not empty switch ($data) { case "exit": //close connection when exit command is given $index = array_search($socket, $read_sockets); unset($read_sockets[$index]); socket_close($socket); echo "[".date('Y-m-d H:i:s')."] Client #".($index-1)." disconnected (connections: ".count($read_sockets)."/".SOMAXCONN.")\n"; break; default: //for experimental purposes, write the given data back socket_write($socket, "\n you wrote: ".$data); } } } } } } socket_close($master); //close the socket echo "[".date('Y-m-d H:i:s')."] SERVER CLOSED.\n"; ?>

  Read the article

• LINQ EF not saving to database...

  - by Keith Barrows

  I guess this is a continuation of the last question I asked: http://stackoverflow.com/questions/2587542/bulk-insert-and-update-with-ado-net-entity-framework. I am not getting any errors while doing inserts yet no data is actually going into my DB. My DB is a SDF file (SQL CE). Any ideas what to check? My app.config looks like: <?xml version="1.0" encoding="utf-8"?> <configuration> <configSections> </configSections> <connectionStrings> <add name="Lab_Use_Billing.Properties.Settings.LabUseConnectionString" connectionString="Data Source=|DataDirectory|\Models\LabUse.sdf" providerName="Microsoft.SqlServerCe.Client.3.5" /> <add name="LabUseEntities" connectionString="metadata=res://*/Models.LabUseEntities.csdl|res://*/Models.LabUseEntities.ssdl|res://*/Models.LabUseEntities.msl; provider=System.Data.SqlServerCe.3.5; provider connection string=&quot;Data Source=|DataDirectory|\Models\LabUse.sdf&quot;" providerName="System.Data.EntityClient" /> </connectionStrings> </configuration> TIA

  Read the article

• Force blocking read after EAGAIN?

  - by Daniel Trebbien

  I have a file descriptor that is open for reading which may be non-blocking. What I need to do is simply read all data until reaching EOF and write that data to a writable file descriptor. As the process that performs this copying is not "aware" of anything that is going on around it, I don't think that I can do something useful while waiting for data, and I don't want to use a while loop (while errno is not EAGAIN) because I think that it would be wasteful. Is there a way to block or otherwise suspend execution of the copying process until data becomes available?

  Read the article

• Forcibly clear memory in java

  - by MBennett

  I am writing an application in java that I care about being secure. After encrypting a byte array, I want to forcibly remove from memory anything potentially dangerous such as the key used. In the following snippet key is a byte[], as is data. SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES"); Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec); byte[] encData = cipher.doFinal(data, 0, data.length); Arrays.fill(key, (byte)0); As far as I understand, the last line above overwrites the key with 0s so that it no longer contains any dangerous data, but I can't find a way to overwrite or evict secretKeySpec or cipher similarly. Is there any way to forcibly overwrite the memory held by secretKeySpec and cipher, so that if someone were to be able to view the current memory state (say, via a cold boot attack), they would not get access to this information?

  Read the article

• JavaScript (via Greasemonkey) failing to set "title" attributes on <a> tags

  - by rjray

  I have the following (fairly) simple JavaScript snippet that I have wired into Greasemonkey. It goes through a page, looks for <a> tags whose href points to tinyurl.com, and adds a "title" attribute that identifies the true destination of the link. Much of the important code comes from an older (unsupported) Greasemonkey script that quits working when the inner component that held the XPath implementation changed. My script: (function() { var providers = new Array(); providers['tinyurl.com'] = function(link, fragment) { // This is mostly taken from the (broken due to XPath component // issues) tinyurl_popup_preview script. link.title = "Loading..."; GM_xmlhttpRequest({ method: 'GET', url: 'http://preview.tinyurl.com/' + fragment, onload: function(res) { var re = res.responseText.match("<blockquote><b>(.+)</b></blockquote>"); if (re) { link.title = re[1].replace(/\<br \/\>/g, "").replace(/&amp;/g, "&"); } else { link.title = "Parsing failed..."; } }, onerror: function() { link.title = "Connection failed..."; } }); }; var uriPattern = /(tinyurl\.com)\/([a-zA-Z0-9]+)/; var aTags = document.getElementsByTagName("a"); for (i = 0; i < aTags.length; i++) { var data = aTags[i].href.match(uriPattern); if (data != null && data.length > 1 && data[2] != "preview") { var source = data[1]; var fragment = data[2]; var link = aTags[i]; aTags[i].addEventListener("mouseover", function() { if (link.title == "") { (providers[source])(link, fragment); } }, false); } } })(); (The reason the "providers" associative array is set up the way it is, is so that I can expand this to cover other URL-shortening services as well.) I have verified that all the various branches of code are being reached correctly, in cases where the link being examined does and does not match the pattern. What isn't happening, is any change to the "title" attribute of the anchor tags. I've watched this via Firebug, thrown alert() calls in left and right, and it just never changes. In a previous iteration all expressions of the form: link.title = "..."; had originally been: link.setAttribute("title", "..."); That didn't work, either. I'm no newbie to JavaScript OR Greasemonkey, but this one has me stumped!

  Read the article

• Jquery ui autocomplete different source

  - by voidnull

  Hi i try to use jquery ui autocomplete. I have different autocomplete field in one page and i need to get data with different sources (different url) depend to wich autocomplete field is used. i know how can i get the typed data (request.term), but i cant find the way to get the selected field ID. $(".ac").autocomplete({ source: function(request, response) { id = '??? the actually used field #id ???'; $.ajax({ type: "POST", url: "/admin_/sql/autocomplete/"+id, data: "test=...", async: false, success: function(data) { } }); }, search: function() { // }, focus: function() { // return false; }, select: function(event, ui) { // return false; } });

  Read the article

• Is typeid of type name always evaluated at compile time in c++ ?

  - by cyril42e

  I wanted to check that typeid is evaluated at compile time when used with a type name (ie typeid(int), typeid(std::string)...). To do so, I repeated in a loop the comparison of two typeid calls, and compiled it with optimizations enabled, in order to see if the compiler simplified the loop (by looking at the execution time which is 1us when it simplifies instead of 160ms when it does not). And I get strange results, because sometimes the compiler simplifies the code, and sometimes it does not. I use g++ (I tried different 4.x versions), and here is the program: #include <iostream> #include <typeinfo> #include <time.h> class DisplayData {}; class RobotDisplay: public DisplayData {}; class SensorDisplay: public DisplayData {}; class RobotQt {}; class SensorQt {}; timespec tp1, tp2; const int n = 1000000000; int main() { int avg = 0; clock_gettime(CLOCK_REALTIME, &tp1); for(int i = 0; i < n; ++i) { // if (typeid(RobotQt) == typeid(RobotDisplay)) // (1) compile time // if (typeid(SensorQt) == typeid(SensorDisplay)) // (2) compile time if (typeid(RobotQt) == typeid(RobotDisplay) || typeid(SensorQt) == typeid(SensorDisplay)) // (3) not compile time ???!!! avg++; else avg--; } clock_gettime(CLOCK_REALTIME, &tp2); std::cout << "time (" << avg << "): " << (tp2.tv_sec-tp1.tv_sec)*1000000000+(tp2.tv_nsec-tp1.tv_nsec) << " ns" << std::endl; } The conditions in which this problem appear are not clear, but: - if there is no inheritance involved, no problem (always compile time) - if I do only one comparison, no problem - the problem only appears only with a disjunction of comparisons if all the terms are false So is there something I didn't get with how typeid works (is it always supposed to be evaluated at compilation time when used with type names?) or may this be a gcc bug in evaluation or optimization? About the context, I tracked down the problem to this very simplified example, but my goal is to use typeid with template types (as partial function template specialization is not possible). Thanks for your help!

  Read the article

• android populating gridivew from a url string

  - by user1685991

  I am building an android application in which i am trying to read data from a url and want to display the data in a gridview. But i have some problem or dont understand to how to display the array list on grdiview. Here is my code for reading data from php url ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); //http post try{ HttpClient httpclient = new DefaultHttpClient(); HttpPost httppost = new HttpPost("http://sml.com.pk/a/smldb.php"); httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); HttpResponse response = httpclient.execute(httppost); HttpEntity entity = response.getEntity(); is = entity.getContent(); }catch(Exception e){ Log.e("log_tag", "Error in http connection"+e.toString()); } //convert response to string try{ BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8); sb = new StringBuilder(); sb.append(reader.readLine() + "\n"); String line="0"; while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } is.close(); result=sb.toString(); }catch(Exception e){ Log.e("log_tag", "Error converting result "+e.toString()); } //paring data double des; double value; try{ jArray = new JSONArray(result); JSONObject json_data=null; for(int i=0;i<jArray.length();i++){ json_data = jArray.getJSONObject(i); LAT=json_data.getDouble("TITLE"); LANG=json_data.getDouble("A"); } } catch(JSONException e1){ Toast.makeText(getBaseContext(), "No Vehicles Found" ,Toast.LENGTH_LONG).show(); } catch (ParseException e1) { e1.printStackTrace(); } Here TITLE and A are my two columns of DB Table and i want to display them on gridview please any one help me to do this according to my current code. Here is my live url for data string http://sml.com.pk/a/smldb.php

  Read the article

• Objective C: Compare timeInMillis with current time

  - by Srivathsan Canchi

  Hello, In my iPhone application, I need to calculate the time difference between the time a message was created on the server, and the time my phone received it. The server (Java) puts in a number returned by System.currentTimeMillis() as metadata along with the message. How do I compare this number with the current time on the device? Could not find a suitable NSDate method to do this comparison. Thanks in advance!

  Read the article

• How to show 0 when no row found

  - by user1685991

  I have a SQL query in which I am passing sysdate to the query problem is that when there is no matching date in table with sysdate then it don't shows the zero even if there is nvl applied here is my query select * from molasses where trunc(trn_dte) = trunc(sysdate) But it show data only when current date is present in table but I want to show zero if no data found in table.please help me to do this in oracle 10 g. Because some times the situation is like above and I have to display zero when no data found

  Read the article

• test="" on a boolean always returns true xslt

  - by user70448

  Why does <xsl:if test="<XPATH to boolean value here>"> ... </xsl:if> ALWAYS return true? Since boolean can be 0,1,"false" and "true" by definition, the ONLY way to test for a boolean value is to do string comparison against these. This can't be right.

  Read the article

• Looking for suggestions about an architecture of a MultiThreaded app.

  - by Dimitri

  Hello everyone. I am looking to develop a multithreaded application that will be running in unconditional loop and processing high volume of data. High volume is 2000+ records per minute. Processing will involve data retrieval, calculations and data updates. I need the application to perform so that there is virtually no back log, meaning i need to be able to finish up all of the 2000 points in one minute or even faster. Our current implementation features a multithreaded application that is spawn multiple times (from 10 to 20) and we are noticing that it's not handling data as expected and i even feel that instances of the application compete with each other for processor time and eventually if not slowing, not benefiting each other for sure. I would like to know what would be the best approach: have a single instance running but maximize threads that can run simultaneously? or is there other ways i don't know? I'm open to suggestions. Thank you in advance

  Read the article

• Escaping if/else in Jade template

  - by Collin Estes

  So I have a simply block of html in my jade template with a loop: each dude, i in dudes div(class='someClass') div.otherStuff span.someContent #{name} I want to apply a data attribute to my top most div when a certain looping condition is met, in this case the first dude, I set it up like this each dude, i in dudes if i == 0 div(class='someClass, data-someAttr='first dude') else div(class='someClass') div.otherstuff span.someContent Setup like this it causes the div.otherStuff div and the span.someContent to only display on the else condition. I've moved the tab spaces around on those items but I can't get it escape that else and give the div.otherStuff and span.someContent to both the first dude and the subsequent dudes after that. I've also tried setting that data attr to a variable and trying to apply it that way but without any success. What I end up doing to get around it is this: each dude, i in dudes if i == 0 div(class='someClass, data-someAttr='first dude') div.otherstuff span.someContent else div(class='someClass') div.otherstuff span.someContent How do I escape that if/else so I dont have to duplicate the div.otherStuff and span.someContent?

  Read the article

• why does my <br> not work ?

  - by Vince

  I am returning a PHP array back to a JQuery call for appending into a div called "name-data". I want my array to be listed vertically, so I concatenate a br tag in the PHP however, when it gets to the HTML page the br is not being rendered, it just comes out as text. I have tried the various forms of br all without luck. I am new to JQuery - What am I doing wrong ? Many Thanks ! PHP: $result = mysqli_query($con,"SELECT FirstName FROM customer limit 5"); while($row = mysqli_fetch_array($result)) { echo $row['FirstName']."<br />"; } JQuery: $('input#name-submit').on('click',function(){ var name = $('input#name').val(); if($.trim(name) !=''){ $.post('search.php',{name:name}, function(data){ $('div#name-data').text(data); }); } }); HTML Name:<input type="text" id="name"> <input type="submit" id="name-submit" value="grab"> <div id="name-data"> </div>

  Read the article

• Page_Load after Modal Popup

  - by n0chi

  I have a page with a user control which gets some data updated via a modal popup. Upon clicking "ok" on the modal popup - the new data is being written to the database - but the base page doesnt "reload" to show the updated data. How do I get that to happen?

  Read the article

• Objective C - Parse NSData

  - by EZFrag

  I have the following data inside an NSData object: <00000000 6f2d840e 31504159 2e535953 2e444446 3031a51b 8801015f 2d02656e 9f110101 bf0c0cc5 0affff3f 00000003 ffff03 I'm having issues parsing this data. This data contains information which is marked by tags Tag 1 is from byte value 0x84 to 0xa5 Tag 2 is from byte value 0xa5 to 0x88 Tag 3 is from byte value 0x88 to 0x5f0x2d Tag 4 is from byte value 0x5f0x2d to 0x9f0x11 How would I go about to get those values from the NSData object? Regards, EZFrag

  Read the article

• Where should I store my App specific config files in WPF

  - by Akash Deshpande

  Background : I have some Application Data. i.e. the Database, come important config files. This data is vital for the application to start else it is exited. Problem : Where should I store this data. i.e in which folder and where. Right Now (This is wrong) it is stored in a folder in Debug/App_Data. But is causing issues in git and when we publish the App the data is not found. So where can we store this folder ? Present Structure is "WpfApplication2\WpfApplication2\bin\Debug" These Files need to be present when the app is started. So they need to be a part of the app itself.

  Read the article

• Trying to Insert Text to Access Database with ExecuteNonQueryin VB

  - by user3673701

  I'm working on this feature were i save text from a textbox on my form to a access database file. With the click on my "store" button I want to save the text in the corresponding textbox fields to the fields in my access database for searching and retrieving purposes. Im doing this in VB The problem I run into is the INSERT TO error with my "store" button Any help or insight as to why im getting error would be greatly appreciated. here is my code: Dim con As System.Data.OleDb.OleDbConnection Dim cmd As System.Data.OleDb.OleDbCommand Dim dr As System.Data.OleDb.OleDbDataReader Dim sqlStr As String Private Sub btnStore_Click(sender As Object, e As EventArgs) Handles btnStore.Click con = New System.Data.OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\Eric\Documents\SPC1.2.accdb") con.Open() MsgBox("Initialized") sqlStr = "INSERT INTO Master FADV Calll info (First Name, Last Name, Phone Number, Email, User Id) values (" & txtFirstName.Text & " ' ,'" & txtLastName.Text & "','" & txtPhone.Text & "', '" & txtEmail.Text & "', '" & txtUserID.Text & "', '" & txtOtherOptionTxt.Text & "','" & txtCallDetail.Text & "');" cmd = New OleDb.OleDbCommand(sqlStr, con) cmd.ExecuteNonQuery() <------- **IM RECIVING THE ERROR HERE** MsgBox("Stored") ''pass ther parameter as sq; query, con " connection Obj)" con.Close()'

  Read the article

• How to convert a byte array of 19200 bytes in size where each byte represents 4 pixels (2 bits per p

  - by Klinger

  I am communicating with an instrument (remote controlling it) and one of the things I need to do is to draw the instrument screen. In order to get the screen I issue a command and the instrument replies with an array of bytes that represents the screen. Below is what the instrument manual has to say about converting the response to the actual screen: The command retrieves the framebuffer data used for the display. It is 19200 bytes in size, 2-bits per pixel, 4 pixels per byte arranged as 320x240 characteres. The data is sent in RLE encoded form. To convert this data into a BMP for use in Windows, it needs to be turned into a 4BPP. Also note that BMP files are upside down relative to this data, i.e. the top display line is the last line in the BMP. I managed to unpack the data, but now I am stuck on how to actually go from the unpacked byte array to a bitmap. My background on this is pretty close to zero and my searches have not revealed much either. I am looking for directions and/or articles I could use to help me undestand how to get this done. Any code or even pseudo code would also help. :-) So, just to summarize it all: How to convert a byte array of 19200 bytes in size, where each byte represents 4 pixels (2 bits per pixel), to a bitmap arranged as 320x240 characters. Thanks in advance.

  Read the article

• Choropleth mapping issue in R

  - by chasec

  I am trying to follow the tutorial described here: http://www.thisisthegreenroom.com/2009/choropleths-in-r/ The below code executes, but it is either not matching my dataset with the maps_counties data properly, or it isn't plotting it in the order I would expect. For example, the resulting areas for the greater NYC area show no density while random counties in PA show the highest density. The general format of my data table is: county state count fairfield connecticut 17 hartford connecticut 6 litchfield connecticut 3 new haven connecticut 12 ... ... westchester new york 70 yates new york 1 luzerne pennsylvania 1 Note this data is in order by state and then county and includes data for CT, NJ, NY, & PA. First, I read in my data set: library(maps) library(RColorBrewer) d <- read.table("gissum.txt", sep="\t", header=TRUE) #Concatenate state and county info to match maps library d$stcon <- paste(d$state, d$county, sep=",") #Color bins colors = brewer.pal(5, "PuBu") d$colorBuckets <- as.factor(as.numeric(cut(d$count,c(0,10,20,30,40,50,300)))) Here is my matching mapnames <- map("county",plot=FALSE)[4]$names colorsmatched <- d$colorBuckets [na.omit(match(mapnames ,d$stcon))] Plotting: map("county" ,c("new york","new jersey", "connecticut", "pennsylvania") ,col = colors[d$colorBuckets[na.omit(match(mapnames ,d$stcon))]] ,fill = TRUE ,resolution = 0 ,lty = 0 ,lwd= 0.5 ) map("state" ,c("new york","new jersey", "connecticut", "pennsylvania") ,col = "black" ,fill=FALSE ,add=TRUE ,lty=1 ,lwd=2 ) map("county" ,c("new york","new jersey", "connecticut", "pennsylvania") ,col = "black" ,fill=FALSE ,add=TRUE , lty=1 , lwd=.5 ) title(main="Respondent Home ZIP Codes by County") I am sure I am missing something basic re: the order in which the maps function plots items - but I can't seem to figure it out. Thanks for the help. Please let me know if you need any more information.

  Read the article

• Trying to packetize TCP with non-blocking IO is hard! Am I doing something wrong?

  - by Ricket

  Oh how I wish TCP was packet-based like UDP is! But alas, that's not the case, so I'm trying to implement my own packet layer. Here's the chain of events so far (ignoring writing packets) Oh, and my Packets are very simply structured: two unsigned bytes for length, and then byte[length] data. (I can't imagine if they were any more complex, I'd be up to my ears in if statements!) Server is in an infinite loop, accepting connections and adding them to a list of Connections. PacketGatherer (another thread) uses a Selector to figure out which Connection.SocketChannels are ready for reading. It loops over the results and tells each Connection to read(). Each Connection has a partial IncomingPacket and a list of Packets which have been fully read and are waiting to be processed. On read(): Tell the partial IncomingPacket to read more data. (IncomingPacket.readData below) If it's done reading (IncomingPacket.complete()), make a Packet from it and stick the Packet into the list waiting to be processed and then replace it with a new IncomingPacket. There are a couple problems with this. First, only one packet is being read at a time. If the IncomingPacket needs only one more byte, then only one byte is read this pass. This can of course be fixed with a loop but it starts to get sorta complicated and I wonder if there is a better overall way. Second, the logic in IncomingPacket is a little bit crazy, to be able to read the two bytes for the length and then read the actual data. Here is the code, boiled down for quick & easy reading: int readBytes; // number of total bytes read so far byte length1, length2; // each byte in an unsigned short int (see getLength()) public int getLength() { // will be inaccurate if readBytes < 2 return (int)(length1 << 8 | length2); } public void readData(SocketChannel c) { if (readBytes < 2) { // we don't yet know the length of the actual data ByteBuffer lengthBuffer = ByteBuffer.allocate(2 - readBytes); numBytesRead = c.read(lengthBuffer); if(readBytes == 0) { if(numBytesRead >= 1) length1 = lengthBuffer.get(); if(numBytesRead == 2) length2 = lengthBuffer.get(); } else if(readBytes == 1) { if(numBytesRead == 1) length2 = lengthBuffer.get(); } readBytes += numBytesRead; } if(readBytes >= 2) { // then we know we have the entire length variable // lazily-instantiate data buffers based on getLength() // read into data buffers, increment readBytes // (does not read more than the amount of this packet, so it does not // need to handle overflow into the next packet's data) } } public boolean complete() { return (readBytes > 2 && readBytes == getLength()+2); } Basically I need feedback on my code. Please suggest any improvements. Even overhauling my entire system would be okay, if you have suggestions for how better to implement the whole thing. Book recommendations are welcome too; I love books. I just get the feeling that something isn't quite right.

  Read the article

• Java Synchronized Write Block

  - by ikurtz

  im new to java and i have a question regarding Synchronized. i have the following code for writing to network (simple implementation for now): public void networkSendData(byte[] data){ try { out.write(data); out.flush(); } catch (IOException e) { } } i was wondering if there is a need for block level Synchronized here as im am writing the whole data at once. or is there a chance for race condition? i ask because the data to write is coming for multiple sources. thank you.

  Read the article

< Previous Page | 723 724 725 726 727 728 729 730 731 732 733 734  | Next Page >