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  • NFS-shared file-system is locking up

    - by fredden
    Our NFS-shared file-system is locking up. Please feel free to ask any questions you feel relevant. :) At the time, there are a lot of processes in "disk sleep" state, and the load averages on our machines sky-rocket. The machines are responsive on SSH, but our the majority of our websites (apache+mod_php) just hang, as does our email system (exim+dovecot). Any websites which don't require write access to the file-system continue to operate. The load averages continue to rise until some kind of time-out is reached, but for at least 10-15 minutes. I've seen load averages over 800, yet the machines are still responsive for actions which don't require writing to the shared file-system. I've been investigating a variety of options, which have all turned out to be red-herrings: nagios, proftpd, bind, cron tasks. I'm seeing these messages in the file server's system log: Jul 30 09:37:17 fs0 kernel: [1810036.560046] statd: server localhost not responding, timed out Jul 30 09:37:17 fs0 kernel: [1810036.560053] nsm_mon_unmon: rpc failed, status=-5 Jul 30 09:37:17 fs0 kernel: [1810036.560064] lockd: cannot monitor node2 Jul 30 09:38:22 fs0 kernel: [1810101.384027] statd: server localhost not responding, timed out Jul 30 09:38:22 fs0 kernel: [1810101.384033] nsm_mon_unmon: rpc failed, status=-5 Jul 30 09:38:22 fs0 kernel: [1810101.384044] lockd: cannot monitor node0 Software involved: VMWare, Debian lenny (64bit), ancient Red Hat (32 bit) (version 7 I believe), Debian etch (32bit) NFS, apache2+mod_php, exim, dovecot, bind, amanda, proftpd, nagios, cacti, drbd, heartbeat, keepalived, LVS, cron, ssmtp, NIS, svn, puppet, memcache, mysql, postgres Joomla!, Magento, Typo3, Midgard, Symfony, custom php apps

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  • Disadvantages of MySQL Row Locking

    - by Nyxynyx
    I am using row locking (transactions) in MySQL for creating a job queue. Engine used is InnoDB. SQL Query START TRANSACTION; SELECT * FROM mytable WHERE status IS NULL ORDER BY timestamp DESC LIMIT 1 FOR UPDATE; UPDATE mytable SET status = 1; COMMIT; According to this webpage, The problem with SELECT FOR UPDATE is that it usually creates a single synchronization point for all of the worker processes, and you see a lot of processes waiting for the locks to be released with COMMIT. Question: Does this mean that when the first query is executed, which takes some time to finish the transaction before, when the second similar query occurs before the first transaction is committed, it will have to wait for it to finish before the query is executed? If this is true, then I do not understand why the row locking of a single row (which I assume) will affect the next transaction query that would not require reading that locked row? Additionally, can this problem be solved (and still achieve the effect row locking does for a job queue) by doing a UPDATE instead of the transaction? UPDATE mytable SET status = 1 WHERE status IS NULL ORDER BY timestamp DESC LIMIT 1

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  • Escaping '“' with regular double quotes using Ruby regex

    - by DavidP6
    I have text that has these fancy double quotes: '“' and I would like to replace them with regular double quotes using Ruby gsub and regex. Here's an example and what I have so far: sentence = 'This is a quote, “Hey guys!”' I couldn't figure out how to escape double quotes so I tried using 34.chr: sentence.gsub("“",34.chr). This gets me close but leaves a back slash in front of the double quote: sentence.gsub("“",34.chr) => 'This is a quote, \"Hey guys!”'

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  • iphone - double tap fail safe way

    - by mike
    I am trying to detect double taps on a view, but when the double tap comes, the first tap triggers an action on TouchesBegan, so, before detecting a double tap a single tap is always detected first. How can I make this in a way that just detects the double tap? I cannot use OS 3.x gestures, because I have to make it compatible with old OS versions. thanks

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  • How is IObservable<double>.Average supposed to work?

    - by Dan Tao
    Update Looks like Jon Skeet was right (big surprise!) and the issue was with my assumption about the Average extension providing a continuous average (it doesn't). For the behavior I'm after, I wrote a simple ContinuousAverage extension method, the implementation of which I am including here for the benefit of others who may want something similar: public static class ObservableExtensions { private class ContinuousAverager { private double _mean; private long _count; public ContinuousAverager() { _mean = 0.0; _count = 0L; } // undecided whether this method needs to be made thread-safe or not // seems that ought to be the responsibility of the IObservable (?) public double Add(double value) { double delta = value - _mean; _mean += (delta / (double)(++_count)); return _mean; } } public static IObservable<double> ContinousAverage(this IObservable<double> source) { var averager = new ContinuousAverager(); return source.Select(x => averager.Add(x)); } } I'm thinking of going ahead and doing something like the above for the other obvious candidates as well -- so, ContinuousCount, ContinuousSum, ContinuousMin, ContinuousMax ... perhaps ContinuousVariance and ContinuousStandardDeviation as well? Any thoughts on that? Original Question I use Rx Extensions a little bit here and there, and feel I've got the basic ideas down. Now here's something odd: I was under the impression that if I wrote this: var ticks = Observable.FromEvent<QuoteEventArgs>(MarketDataProvider, "MarketTick"); var bids = ticks .Where(e => e.EventArgs.Quote.HasBid) .Select(e => e.EventArgs.Quote.Bid); var bidsSubscription = bids.Subscribe( b => Console.WriteLine("Bid: {0}", b) ); var avgOfBids = bids.Average(); var avgOfBidsSubscription = avgOfBids.Subscribe( b => Console.WriteLine("Avg Bid: {0}", b) ); I would get two IObservable<double> objects (bids and avgOfBids); one would basically be a stream of all the market bids from my MarketDataProvider, the other would be a stream of the average of these bids. So something like this: Bid Avg Bid 1 1 2 1.5 1 1.33 2 1.5 It seems that my avgOfBids object isn't doing anything. What am I missing? I think I've probably misunderstood what Average is actually supposed to do. (This also seems to be the case for all of the aggregate-like extension methods on IObservable<T> -- e.g., Max, Count, etc.)

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  • Distinguish between single and double click events in Qt

    - by Jesse
    I have a QAbstractItemView that needs to react to single and double click events. The actions are different depending on whether it was single clicked or double clicked. The problem that is occurring is that the single click event is received prior to the double click event. Is there a recommended way/best practice for distinguishing between the two? I don't want to perform the single click action when the user has actually double clicked. I am using Qt 4.6

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  • How to make double[,] x_List in C#3.0?

    - by Newbie
    I ned to implement the multi-linear regression in C#(3.0) by using the LinESt function of Excel. Basically I am trying to achieve =LINEST(ACL_returns!I2:I10,ACL_returns!J2:K10,FALSE,TRUE) So I have the data as below double[] x1 = new double[] { 0.0330, -0.6463, 0.1226, -0.3304, 0.4764, -0.4159, 0.4209, -0.4070, -0.2090 }; double[] x2 = new double[] { -0.2718, -0.2240, -0.1275, -0.0810, 0.0349, -0.5067, 0.0094, -0.4404, -0.1212 }; double[] y = new double[] { 0.4807, -3.7070, -4.5582, -11.2126, -0.7733, 3.7269, 2.7672, 8.3333, 4.7023 }; I have to write a function whose signature will be Compute(double[,] x_List, double[] y_List) { LinEst(x_List,y_List, true, true); < - This is the excel function that I will call. } My question is how by using double[] x1 and double[] x2 I will make double[,] x_List ? I am using C#3.0 and framework 3.5. Thanks in advance

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  • building jquery checkbox - can't set checked value

    - by benpage
    this seems straightforward enough, I don't know if it's a bug, or just something I'm doing wrong. What I want to do is build a checkbox input in jquery, then return the string of the input. I have this code: var obj = $('<input>'); obj.attr('disabled', 'disabled'); obj.attr('type', 'checkbox'); obj.attr('checked', 'checked'); // this does not work! no matter how i try to render this obj, the 'checked' attribute never gets outputted. So I have tried: $('<div>').append(obj).remove().html(); and it returns: <input type="checkbox" disabled="disabled" /> I have tried setting an id attribute, it makes no difference. I have also tried this but it doesn't work: obj.attr('checked', true); Any suggestions on how to get the input tag rendered with the checked attribute set to 'checked' (via jquery)? I realise I can just do this with string concatenation, but now I really want to know why it's not working the way it should.

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  • MVVM-Light EventToCommand Behavior for CheckBox Checked/Unchecked in Silverlight

    - by George Durzi
    I would like to handle the Checked and Unchecked events of a Checkbox control and execute a command in my ViewModel. I wired up an EventTrigger for both the Checked and Unchecked events as follows: <CheckBox x:Name="chkIsExtendedHr" IsChecked="{Binding Schedule.Is24Hour, Mode=TwoWay}"> <i:Interaction.Triggers> <i:EventTrigger EventName="Checked"> <GalaSoft_MvvmLight_Command:EventToCommand CommandParameter="{Binding IsChecked, ElementName=chkIsExtendedHr}" Command="{Binding Path=SetCloseTime, Mode=OneWay}" /> </i:EventTrigger> <i:EventTrigger EventName="Unchecked"> <GalaSoft_MvvmLight_Command:EventToCommand CommandParameter="{Binding IsChecked, ElementName=chkIsExtendedHr}" Command="{Binding Path=SetCloseTime, Mode=OneWay}" /> </i:EventTrigger> </i:Interaction.Triggers> </CheckBox> I defined a RelayCommand in my ViewModel and wired up an action for it: public RelayCommand<Boolean> SetCloseTime{ get; private set; } ... SetCloseTime= new RelayCommand<bool>(ExecuteSetCloseTime); The parameter in the action for the command always resolves to the previous state of the CheckBox, e.g. false when the CheckBox is checked, and true when the CheckBox is unchecked. void ExecuteSetCloseTime(bool isChecked) { if (isChecked) { // do something } } Is this expected behavior? I have a workaround where I have separate triggers (and commands) for the Checked and Unchecked and use a RelayCommand instead of RelayCommand<bool>. Each command executes correctly when the CheckBox is checked and unchecked. Feels a little dirty though - even dirtier than having UI code in my ViewModel :) Thanks

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  • radiobutton checked on condition in jquery

    - by RememberME
    I have the following fields: <label>Company Type:</label> <label for="primary"><input onclick="javascript: $('#sec').hide('slow');$('#primary_company').find('option:first').attr('selected','selected');" type="radio" runat="server" name="companyType" id="primary" />Primary</label> <label for="secondary"><input onclick="javascript: $('#sec').show('slow');" type="radio" runat="server" name="companyType" id="secondary" />Secondary</label> <div id="sec"> <fieldset> <label for="primary_company">Primary Company:</label> <%= Html.DropDownList("primary_company", Model.SelectPrimaryCompanies, "** Select Primary Company **") %> </fieldset> If there is a primary_company, then the secondary radio button should be selected. If there is no primary_company, then the primary radio button should be selected. Here is my jQuery: $(document).ready(function() { if ($('#primary_company').val().length > 0) { $('#secondary').attr({ checked: true }); } else { $("#primary").attr('checked', true ); $('#sec').hide(); } The sec div hides and shows properly, but a radio button is never selected. I've tried .attr('checked', 'checked') and .attr({ checked: true }) and .attr('checked', true) but nothing is ever selected.

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  • How Do i handle both the checked and clicked events in Jquery

    - by Someone
    Say I have a form and onload of that form I have 2 radio buttons say "yes" or "no " I have set of action to perform when we select either one radio button .Say if we select "yes " //Onload of Form if(("#yes:checked")){ $("#table").show(); $("#div1").show(); $("#div2").show(); alert("Checkedd on Load"); } //for click $("#yes").bind('click',function(){ $("#table").show(); $("#div1").show(); $("#div2").show(); alert("Checked by Click"); }); }); Iam Writing the same repeated lines of code for two similar set of events .Is There anyway to combine the "Checked" and "Clicked" events Say if i do inthis way than "Checked" doesnot get called untill "Clicked"?Is there any other way to do it. $("#yes").bind('click',function(){ if(("#yes:checked")){ $("#table").show(); $("#div1").show(); $("#div2").show(); alert("Checked by Click"); } }); });

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  • checking all checkboxes are checked using jquery

    - by kumar
    Hello friends I have two button one is SelectAll then MassEdit.. my code for select all is $('#btnAll').click(function() { $('#ExceptionDetails input[type=checkbox]').attr('checked', 'checked'); }); this check all the chekcboxes in my view.. then I have other button code which needs to take only checked checkbox information to send it other page.. to display only checked checkbox users.. $('#btnMassEdit').click(function() { $('#ExceptionDetails input[type=checkbox]').each(function() { if ($(this).attr('checked')) { $('#specialist-tab').tabs('url', 3, '<%=Url.Action("getmasseditexceptions", "Expense", new { @GUI_SPEC_STAT_DSPL = GUI_SPEC_STAT_DSPL, @C_EXCPT_CATG = C_EXCPT_CATG, @C_EXCPT_TYPE = C_EXCPT_TYPE })%>').tabs('enable', 3).tabs('select', 3); return false; } else { alert("please select atleast one exceptin"); $().ShowDialog('Please Select Exception, Select atleast one exception'); return false; } }); }); i have a fieldset which is ExceptionDetails..one field set have only one checkbox.. but my view having multiple fieldsets for differnt exceptions.. I need to check all the filedsset which is checked or not what ever the fieldset checkboxes are check I need to take only that exception to pass to the other page.. thanks

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  • Sound does not play when locking WinXP

    - by Christopher
    If I press the Windows-L combination to lock my PC the "Windows Logoff" sound does not play. It used to but at some point it stopped. I installed only trustworthy apps on my system and it is pretty clean so I don't think it is a virus. I checked the sounds in the control panel and "Windows Logoff" is set. Is there a sound associated with the key combination? Perhaps something in the registry? Any help is appreciated.

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  • Why doesn't my form post when I disable the submit button to prevent double clicking?

    - by John MacIntyre
    Like every other web developer on the planet, I have an issue with users double clicking the submit button on my forms. My understanding is that the conventional way to handle this issue, is to disable the button immediately after the first click, however when I do this, it doesn't post. I did do some research on this, god knows there's enough information, but other questions like Disable button on form submission, disabling the button appears to work. The original poster of Disable button after submit appears to have had the same problem as me, but there is no mention on how/if he resolved it. Here's some code on how to repeat it (tested in IE8 Beta2, but had same problem in IE7) My aspx code <%@ Page Language="C#" CodeFile="Default.aspx.cs" Inherits="_Default" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <script language="javascript" type="text/javascript"> function btn_onClick() { var chk = document.getElementById("chk"); if(chk.checked) { var btn = document.getElementById("btn"); btn.disabled = true; } } </script> <body> <form id="form1" runat="server"> <asp:Literal ID="lit" Text="--:--:--" runat="server" /> <br /> <asp:Button ID="btn" Text="Submit" runat="server" /> <br /> <input type="checkbox" id="chk" />Disable button on first click </form> </body> </html> My cs code using System; public partial class _Default : System.Web.UI.Page { protected override void OnInit(EventArgs e) { base.OnInit(e); btn.Click += new EventHandler(btn_Click); btn.OnClientClick = "btn_onClick();"; } void btn_Click(object sender, EventArgs e) { lit.Text = DateTime.Now.ToString("HH:mm:ss"); } } Notice that when you click the button, a postback occurs, and the time is updated. But when you check the check box, the next time you click the button, the button is disabled (as expected), but never does the postback. WHAT THE HECK AM I MISSING HERE??? Thanks in advance.

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  • How to escape or remove double quotes in rsyslog template

    - by Evgeny
    I want rsyslog to write log messages in JSON format, which requires to use double-quotes (") around strings. Problem is that values sometime include double-quotes themselves, and those need to be escaped - but I can't figure out how to do that. Currently my rsyslog.conf contains this format that I use (a bit simplified): $template JsonFormat,"{\"msg\":\"%msg%\",\"app-name\":\"%app-name%\"}\n",sql But when a msg arrives that contains double quotes, the JSON is broken, example: user pid=21214 uid=0 auid=4294967295 msg='PAM setcred: user="oracle" exe="/bin/su" (hostname=?, addr=?, terminal=? result=Success)' turns into: {"msg":"user pid=21214 uid=0 auid=4294967295 msg='PAM setcred: user="oracle" exe="/bin/su" (hostname=?, addr=?, terminal=? result=Success)'","app-name":"user"} but what I need it to become is: {"msg":"user pid=21214 uid=0 auid=4294967295 msg='PAM setcred: user=\"oracle\" exe=\"/bin/su\" (hostname=?, addr=?, terminal=? result=Success)'","app-name":"user"}

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  • Iphone: UIWebview and double taps

    - by Eyal
    I would like to trap a double tap event in a UIWebView. I have derived a class from UIWebController. When I double tap it seams that the UIWebController itself is responding to my double taps instead of my class. The weird thing is that when I change the inheritance to inherit from UIView everything works just fine. Below are snippets from my code which is supposed to invoke a pop-up when double tapped. In the init function: //Setup action for double tap UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleDoubleTap:)]; tap.numberOfTapsRequired = 2; [super addGestureRecognizer:tap]; [tap release]; And Also: - (void)handleDoubleTap:(UIGestureRecognizer *)gestureRecognizer { UIAlertView *someError = [[UIAlertView alloc] initWithTitle: @"Network error" message: @"Hello" delegate: self cancelButtonTitle: @"Ok" otherButtonTitles: nil]; [someError show]; [someError release]; //[[NSNotificationCenter defaultCenter] postNotificationName:NOTIFICATION_FLIP_TO_PAGE_VIEW object:nil]; }

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  • Spring MVC defaultValue for Double

    - by mlathe
    Hi All, I'm trying to build a controller like this: @RequestMapping(method = {RequestMethod.GET}, value = "/users/detail/activities.do") public View foo(@RequestParam(value = "userCash", defaultValue="0.0") Double userCash) { System.out.println("foo userCash=" + userCash); } This works fine: http://localhost/app/users/detail/activities.do?userCash=123& but in this one userCash==null despite the default value http://localhost/app/users/detail/activities.do?userCash=& From some digging it seems like the first one works b/c of a Editor binding like this: binder.registerCustomEditor(Double.class, new CustomNumberEditor(Double.class, false)); The trouble is that the second param (ie false) defines whether blank values are allowed. If i set that to true, than the system considers the blank input as valid so i get a null Double class. If i set it to false then the system chokes on the blank input string with: org.springframework.beans.TypeMismatchException: Failed to convert value of type 'java.lang.String' to required type 'double'; nested exception is java.lang.NumberFormatException: empty String Does anyone know how to get the defaultValue to work for Doubles? Thanks --Matthias

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  • Explanation of casting/conversion int/double in C#

    - by cad
    I coded some calculation stuff (I copied below a really simplifed example of what I did) like CASE2 and got bad results. Refactored the code like CASE1 and worked fine. I know there is an implicit cast in CASE 2, but not sure of the full reason. Any one could explain me what´s exactly happening below? //CASE 1, result 5.5 double auxMedia = (5 + 6); auxMedia = auxMedia / 2; //CASE 2, result 5.0 double auxMedia1 = (5 + 6) / 2; //CASE 3, result 5.5 double auxMedia3 = (5.0 + 6.0) / 2.0; //CASE 4, result 5.5 double auxMedia4 = (5 + 6) / 2.0; My guess is that /2 in CASE2 is casting (5 + 6) to int and causing round of division to 5, then casted again to double and converted to 5.0. CASE3 and CASE 4 also fixes the problem.

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  • NullPointerException, Collections not storing data?

    - by Elliott
    Hi there, I posted this question earlier but not with the code in its entirety. The coe below also calls to other classes Background and Hydro which I have included at the bottom. I have a Nullpointerexception at the line indicate by asterisks. Which would suggest to me that the Collections are not storing data properly. Although when I check their size they seem correct. Thanks in advance. PS: If anyone would like to give me advice on how best to format my code to make it readable, it would be appreciated. Elliott package exam0607; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.net.URL; import java.util.Collection; import java.util.Scanner; import java.util.Vector; import exam0607.Hydro; import exam0607.Background;// this may not be necessary???? FIND OUT public class HydroAnalysis { public static void main(String[] args) { Collection hydroList = null; Collection backList = null; try{hydroList = readHydro("http://www.hep.ucl.ac.uk/undergrad/3459/exam_data/2006-07/final/hd_data.dat");} catch (IOException e){ e.getMessage();} try{backList = readBackground("http://www.hep.ucl.ac.uk/undergrad/3459/exam_data/2006-07/final/hd_bgd.dat"); //System.out.println(backList.size()); } catch (IOException e){ e.getMessage();} for(int i =0; i <=14; i++ ){ String nameroot = "HJK"; String middle = Integer.toString(i); String hydroName = nameroot + middle + "X"; System.out.println(hydroName); ALGO_1(hydroName, backList, hydroList); } } public static Collection readHydro(String url) throws IOException { URL u = new URL(url); InputStream is = u.openStream(); InputStreamReader isr = new InputStreamReader(is); BufferedReader b = new BufferedReader(isr); String line =""; Collection data = new Vector(); while((line = b.readLine())!= null){ Scanner s = new Scanner(line); String name = s.next(); System.out.println(name); double starttime = Double.parseDouble(s.next()); System.out.println(+starttime); double increment = Double.parseDouble(s.next()); System.out.println(+increment); double p = 0; double nterms = 0; while(s.hasNextDouble()){ p = Double.parseDouble(s.next()); System.out.println(+p); nterms++; System.out.println(+nterms); } Hydro SAMP = new Hydro(name, starttime, increment, p); data.add(SAMP); } return data; } public static Collection readBackground(String url) throws IOException { URL u = new URL(url); InputStream is = u.openStream(); InputStreamReader isr = new InputStreamReader(is); BufferedReader b = new BufferedReader(isr); String line =""; Vector data = new Vector(); while((line = b.readLine())!= null){ Scanner s = new Scanner(line); String name = s.next(); //System.out.println(name); double starttime = Double.parseDouble(s.next()); //System.out.println(starttime); double increment = Double.parseDouble(s.next()); //System.out.println(increment); double sum = 0; double p = 0; double nterms = 0; while((s.hasNextDouble())){ p = Double.parseDouble(s.next()); //System.out.println(p); nterms++; sum += p; } double pbmean = sum/nterms; Background SAMP = new Background(name, starttime, increment, pbmean); //System.out.println(SAMP); data.add(SAMP); } return data; } public static void ALGO_1(String hydroName, Collection backgs, Collection hydros){ //double aMin = Double.POSITIVE_INFINITY; //double sum = 0; double intensity = 0; double numberPN_SIG = 0; double POSITIVE_PN_SIG =0; //int numberOfRays = 0; for(Hydro hd: hydros){ System.out.println(hd.H_NAME); for(Background back : backgs){ System.out.println(back.H_NAME); if(back.H_NAME.equals(hydroName)){//ERROR HERE double PN_SIG = Math.max(0.0, hd.PN - back.PBMEAN); numberPN_SIG ++; if(PN_SIG 0){ intensity += PN_SIG; POSITIVE_PN_SIG ++; } } } double positive_fraction = POSITIVE_PN_SIG/numberPN_SIG; if(positive_fraction < 0.5){ System.out.println( hydroName + "is faulty" ); } else{System.out.println(hydroName + "is not faulty");} System.out.println(hydroName + "has instensity" + intensity); } } } THE BACKGROUND CLASS package exam0607; public class Background { String H_NAME; double T_START; double DT; double PBMEAN; public Background(String name, double starttime, double increment, double pbmean) { name = H_NAME; starttime = T_START; increment = DT; pbmean = PBMEAN; }} AND THE HYDRO CLASS public class Hydro { String H_NAME; double T_START; double DT; double PN; public double n; public Hydro(String name, double starttime, double increment, double p) { name = H_NAME; starttime = T_START; increment = DT; p = PN; } }

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  • Double-tap or two single-taps?

    - by Jaka Jancar
    What is the time limit for two taps to be considered a double-tap, on the iPhone OS? // Edit: Why is this important? In order to handle single-tap and double-tap differently, Apple's guide says to do performSelector...afterDelay with some 'reasonable' interval on first tap (and cancel it later if the second tap is detected). The problem is that if the interval is too short (0.1), the single tap action will be performed even when double-tapping (if relying only on tapCount, that is). If it's too long (0.8), the user will be waiting unnecessarily for the single-tap to be recognized, when there is no possibility for a double-tap. It has to be exactly the correct number, in order to work optimally, but definitely not smaller, or there's a chance for bugs (simultaneous single-tap and double-tap).

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  • static const double in c++

    - by Crystal
    Is this the proper way to use a static const variable? In my top level class (Shape) #ifndef SHAPE_H #define SHAPE_H class Shape { public: static const double pi; private: double originX; double originY; }; const double Shape::pi = 3.14159265; #endif And then later in a class that extends Shape, I use Shape::pi. I get a linker error. I moved the const double Shape::pi = 3.14... to the Shape.cpp file and my program then compiles. Why does that happen? thanks.

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  • Problem in List<double[,]> (C#3.0)

    - by Newbie
    What is wrong with List<double> x = new List<double> { 0.0330, -0.6463, 0.1226, -0.3304, 0.4764, -0.4159, 0.4209, -0.4070, -0.2090, -0.2718, -0.2240, -0.1275, -0.0810, 0.0349, -0.5067, 0.0094, -0.4404, -0.1212 }; List<double> y = new List<double> { 0.4807, -3.7070, -4.5582, -11.2126, -0.7733, 3.7269, 2.7672, 8.3333, 4.7023,0,0,0,0,0,0,0,0,0 }; List z = new List{x,y}; Error: Argument '1': cannot convert from 'System.Collections.Generic.List' to 'double[,]' Help neded.(C#3.0)

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