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  • Another C datatypes question

    - by b-gen-jack-o-neill
    Hello. Well, I completely get the most basic datatypes of C, like short, int, long, float, to be exact, all numerical types.These types are needed to be known perform right operations with right numbers. For example to use FPU to add two float numbers. So the compiler must know what the type is. But, when it comes to characters I am little bit off. I know that basic C datatype char is there for ASCII characters coding. But what I don´t know is, why you even need another datatype for characters. Why could not you just use 1 byte integer value to store ASCII character. If you call printf, you apecify the datatype in the call, so you could say to printf that the integer represents ASCII character. I dont know how cout resolves datatype, but I guess you could just specify it somehow. Another thing is, when you want to use Unicode, you must use datatype wchar. But, what if I would like to use some another, for example ISO, or Windows coding instead of UTF? Becouse wchar codes characters as UTF-16 or UTF-32 (I read its compiler specific). And, what if I would want to use for example some imaginary new 8 byte text coding? What datatype should I use for it? I am actually pretty confused of this, becouse I always expected that if I want to use UTF-32 instead of ASCII, I just tell compiler "get UTF-32 value of the character I typed and save it into 4 char field." I thought that text coding is to be dealt with by the end, print function for example. That I just need to specify the coding for the compiler to use, since Windows doesent use ASCII in win32 apps, I guess C compiler must convert the char I typed to ASCII from whatever the type is that windows sends to the C editor. And the last thing is, what if I want to use for example 25 Byte integer for some high math operations? C has no specify-yourself datatype. Yes, I know that this would be difficult since all the math operations would need to be changed, becouse CPU can not add 25 Bytes numbers together. But is there a way to do it? Or is there some math library for it? What if I want to compute Pi to 1000000000000000 digits? :) I know my question is pretty long, but I just wanted to explain my thoughts the best I can in English, since its not my native language it is difficult. And I believe there is simple answer to my question(s), something I missed that explains everything. I read lot about text coding, C tutorials, but nothing about his. Thank you for your time.

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  • Change Layout Of Text Created In Java [Android]

    - by Dan
    Ok right , i asked how to create a random number from 1-100 for android and i came to this TextView tv = new TextView(this); int random = (int)Math.ceil(Math.random()*101); tv.setText("Your Number Is..."+ random ); What this does is create the default kinda "hello world" style text view and says "Your Number Is.... [Then Random Number] My problem is that i cant change the layout of this text , because it is not defined in XML, if someone could tell me how to change the style , or like make the random number into a string so i could use it for any Textview layout that would be great .. Thanks :)

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  • Javascript Close Browser or goto external site function

    - by aaroninfidel
    Hello, I've been trying to figure out how I can go about creating a javascript function that will only be called when a user is accessing an external site or closing the window to the current site they're on. So far I've come up with this, any help is greatly appreciated. <script type="text/javascript"> window.onbeforeunload = confirmExit; function getAd() { var myAds = new Array(); myAds[0] = "http://localhost/link1"; myAds[1] = "http://localhost/link2"; var randomAd = Math.floor(Math.random() * myAds.length); return myAds[randomAd]; } function confirmExit(){ alert(getAd()); return false; } </script>

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  • is there difference between debug and release reference path while compiling?

    - by Nair
    I am building a SL3 + RIA application in VS2008. When compiled the application in debug mode it compiles fine with out any error, but when I compile the same application with out any code change in release mode I get an error 'The type of namespace name 'BusyIndicator' does not exist in the namespace 'System.Windows.Controls' (are you missing an assembly reference). All the errors are coming from the generated code name.g.cs Just curious anyone run into this problem.

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  • ArithmeticException thrown during BigDecimal.divide

    - by polygenelubricants
    I thought java.math.BigDecimal is supposed to be The Answer™ to the need of performing infinite precision arithmetic with decimal numbers. Consider the following snippet: import java.math.BigDecimal; //... final BigDecimal one = BigDecimal.ONE; final BigDecimal three = BigDecimal.valueOf(3); final BigDecimal third = one.divide(three); assert third.multiply(three).equals(one); // this should pass, right? I expect the assert to pass, but in fact the execution doesn't even get there: one.divide(three) causes ArithmeticException to be thrown! Exception in thread "main" java.lang.ArithmeticException: Non-terminating decimal expansion; no exact representable decimal result. at java.math.BigDecimal.divide It turns out that this behavior is explicitly documented in the API: In the case of divide, the exact quotient could have an infinitely long decimal expansion; for example, 1 divided by 3. If the quotient has a non-terminating decimal expansion and the operation is specified to return an exact result, an ArithmeticException is thrown. Otherwise, the exact result of the division is returned, as done for other operations. Browsing around the API further, one finds that in fact there are various overloads of divide that performs inexact division, i.e.: final BigDecimal third = one.divide(three, 33, RoundingMode.DOWN); System.out.println(three.multiply(third)); // prints "0.999999999999999999999999999999999" Of course, the obvious question now is "What's the point???". I thought BigDecimal is the solution when we need exact arithmetic, e.g. for financial calculations. If we can't even divide exactly, then how useful can this be? Does it actually serve a general purpose, or is it only useful in a very niche application where you fortunately just don't need to divide at all? If this is not the right answer, what CAN we use for exact division in financial calculation? (I mean, I don't have a finance major, but they still use division, right???).

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  • Tools to convert option strict off code into option strict on?

    - by deerchao
    I have to take over a project written in vb.net, which more than 400k lines of code written in option strict off mode. I want to build it under option strict on first before I do anything else -- which maybe converting it into C#. I found there's thousands of lines of code raises compilation error, mostly are about implicit type casts. Is there any tool would help to make it compile under option strict on mode if I don't want to correct every single line manually?

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  • Two GET methods in .htaccess

    - by Wayne
    What way it is to be to get two GET methods in the URL by htaccess? RewriteRule ^adm/(.*)$ adm.php?mode=$1 I've used that for the example URL: http://www.domain.com/adm/thismode Now I want to get two methods like: http://www.domain.com/adm/thismode/othermode I've tried this: RewriteRule ^adm/(.*)$/(.*)$ adm.php?mode=$1&othermode=$2 But doesn't seem to work... how do I get it to do that?

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  • CouchDB Map/Reduce raises execption in reduce function?

    - by fuzzy lollipop
    my view generates keys in this format ["job_id:1234567890", 1271430291000] where the first key element is a unique key and the second is a timestamp in milliseconds. I run my view with this elapsed_time?startkey=["123"]&endkey=["123",{}]&group=true&group_level=1 and here is my reduce function, the intention is to reduce the output to get the earliest and latest timestamps and return the difference between them and now function(keys,values,rereduce) { var now = new Date().valueOf(); var first = Number.MIN_VALUE; var last = Number.MAX_VALUE; if (rereduce) { first = Math.max(first,values[0].first); last = Math.min(last,values[0].last); } else { first = keys[0][0][1]; last = keys[keys.length-1][0][1]; } return {first:now - first, last:now - last}; } and when processing a query it constantly raises the following execption: function raised exception (new TypeError("keys has no properties", "", 1)) I am making sure not to reference keys inside my rereduce block. Why does this function constantly raise this exception?

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  • How to remove adornments like [exec] when using groovy's AntBuilder

    - by Miguel Pardal
    Hi! I'm using Groovy's AntBuilder to execute Ant tasks: def ant = new AntBuilder() ant.sequential { ant.exec(executable: "cmd", dir: "..", resultproperty: "exec-ret-code") { arg(value: "/c") arg(line: "dir") } } The output lines are prefixed by: [exec] Using Ant on the command line, this is turned off by "emacs mode" ant -emacs ... Is there a way to switch to emacs mode using AntBuilder?

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  • sharepoint custom aspx page with database connection

    - by Megini
    hi there i have created a custom aspx page whithin my sharepoint site with a sql server connection to a database on that server to select data when i view the page it works but when another user tries to view it it gives the following error : Server Error in '/' Application. Login failed for user 'GRINCOR\GuguK'. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Data.SqlClient.SqlException: Login failed for user 'GRINCOR\GuguK'. Source Error: The source code that generated this unhandled exception can only be shown when compiled in debug mode. To enable this, please follow one of the below steps, then request the URL: Add a "Debug=true" directive at the top of the file that generated the error. Example: <%@ Page Language="C#" Debug="true" % or: 2) Add the following section to the configuration file of your application: Note that this second technique will cause all files within a given application to be compiled in debug mode. The first technique will cause only that particular file to be compiled in debug mode. Important: Running applications in debug mode does incur a memory/performance overhead. You should make sure that an application has debugging disabled before deploying into production scenario. Stack Trace: [SqlException (0x80131904): Login failed for user 'GRINCOR\GuguK'.] System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +248 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +245 System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +2811 System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK) +53 System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) +327 System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart) +2445370 System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +2445224 System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +354 System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +703 System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) +54 System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) +2414776 System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) +92 System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) +1657 System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +84 System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +1645767 System.Data.SqlClient.SqlConnection.Open() +258 ASP.d7922f0d_ac20_4f87_91a2_a99a52c2b2fa__233736835.DisplayData() in C:\inetpub\wwwroot\wss\VirtualDirectories\80\sites\hrportal2\tester.aspx:151 ASP.d7922f0d_ac20_4f87_91a2_a99a52c2b2fa_233736835._RenderMain(HtmlTextWriter __w, Control parameterContainer) in C:\inetpub\wwwroot\wss\VirtualDirectories\80\sites\hrportal2\tester.aspx:346 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +115 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +240 System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +42 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +240 System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) +253 System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output) +87 System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer) +53 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +240 System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +42 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +240 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +240 System.Web.UI.Page.Render(HtmlTextWriter writer) +38 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +4240 Version Information: Microsoft .NET Framework Version:2.0.50727.3603; ASP.NET Version:2.0.50727.3601 can someone give me a solution to this problem ? i am using sharepoint services 3.0

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  • GLOBAL problem with javascript

    - by Syom
    There is some problem, i can't understand anyway. look at this code please <script type="text/javascript"> function math(x) { var y; y = x*10; alert(y); } </script> <input type="button" onclick="math(0.011)"> What must be alerted after i click on button? i think 0.11, but no, it alerts 0.10999999999999999 explain please this behavior. thanks in advance

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  • Code-Golf: Friendly Number Abbreviator

    - by David Murdoch
    Based on this question: Is there a way to round numbers into a friendly format? THE CHALLENGE - UPDATED! (removed hundreds abbreviation from spec) The shortest code by character count that will abbreviate an integer (no decimals). Code should include the full program. Relevant range is from 0 - 9,223,372,036,854,775,807 (the upper limit for signed 64 bit integer). The number of decimal places for abbreviation will be positive. You will not need to calculate the following: 920535 abbreviated -1 place (which would be something like 0.920535M). Numbers in the tens and hundreds place (0-999) should never be abbreviated (the abbreviation for the number 57 to 1+ decimal places is 5.7dk - it is unneccessary and not friendly). Remember to round half away from zero (23.5 gets rounded to 24). Banker's rounding is verboten. Here are the relevant number abbreviations: h = hundred (102) k = thousand (103) M = million (106) G = billion (109) T = trillion (1012) P = quadrillion (1015) E = quintillion (1018) SAMPLE INPUTS/OUTPUTS (inputs can be passed as separate arguments): First argument will be the integer to abbreviate. The second is the number of decimal places. 12 1 => 12 // tens and hundreds places are never rounded 1500 2 => 1.5k 1500 0 => 2k // look, ma! I round UP at .5 0 2 => 0 1234 0 => 1k 34567 2 => 34.57k 918395 1 => 918.4k 2134124 2 => 2.13M 47475782130 2 => 47.48G 9223372036854775807 3 => 9.223E // ect... . . . Original answer from related question (javascript, does not follow spec): function abbrNum(number, decPlaces) { // 2 decimal places => 100, 3 => 1000, etc decPlaces = Math.pow(10,decPlaces); // Enumerate number abbreviations var abbrev = [ "k", "m", "b", "t" ]; // Go through the array backwards, so we do the largest first for (var i=abbrev.length-1; i>=0; i--) { // Convert array index to "1000", "1000000", etc var size = Math.pow(10,(i+1)*3); // If the number is bigger or equal do the abbreviation if(size <= number) { // Here, we multiply by decPlaces, round, and then divide by decPlaces. // This gives us nice rounding to a particular decimal place. number = Math.round(number*decPlaces/size)/decPlaces; // Add the letter for the abbreviation number += abbrev[i]; // We are done... stop break; } } return number; }

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  • What's the difference between the ruby irb prompt modes?

    - by Steven
    I can change the irb prompt mode with irb --prompt prompt-mode I can see what null and simple does, but I can't tell the difference between null and xmp and the difference between default/classic/inf-ruby. Can someone explain to me what these other modes do? It seems pointless to have multiple modes doing the same thing.

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  • PHP Moving mySQL Tree Node

    - by TK
    I am having trouble trying to move sub nodes or parent nodes up or down... not that good at math. CREATE TABLE IF NOT EXISTS `pages` ( page-id mediumint(8) unsigned NOT NULL AUTO_INCREMENT, page-left mediumint(8) unsigned NOT NULL, page-right smallint(8) unsigned NOT NULL, page-title text NOT NULL, page-content text NOT NULL, page-time int(11) unsigned NOT NULL, page-slug text NOT NULL, page-template text NOT NULL, page-parent mediumint(8) unsigned NOT NULL, page-type text NOT NULL, PRIMARY KEY (page-id) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 ; INSERT INTO pages (page-id, page-left, page-right, page-title, page-content, page-time, page-slug, page-template, page-parent, page-type) VALUES (17, 1, 6, '1', '', 0, 'PARENT', '', 0, ''), (18, 2, 5, '2', '', 0, 'SUB', '', 17, ''), (19, 3, 4, '3', '', 0, 'SUB-SUB', '', 18, ''), (20, 7, 8, '5', '', 0, 'TEST', '', 0, ''); As example how would I move TEST up above PARENT and say move SUB down below SUB-SUB by playing with the page-left/page-right IDs? Code is not required just help with the SQL concept or math for it, would help me understand how to move it better...

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  • How do I create a random method name

    - by Russ Bradberry
    I plan on using JSONP to call an external webservice to get around the fact that I dont want to create a global function that could potentially conflict with the calling page. I thought that creating a random function name and passing it up would work. Something like this: <script src="www.foo.com/b?cb=d357534"> where cb is the callback function name, the server would return d357534({my json data}); what i want to know is how to create the random function name, im sure i could use eval but is this the best way to go about it? essentially, what i am trying to do is this: var d + Math.floor(Math.random()*1000001) = function(){...

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  • New Bluetooth API question

    - by Ralphz
    I have written a small app that puts my bluetooth in discoverable mode for a long time (G1 - API 1.6). I use that along with small program on windows to lock/unlock the computer if the phone is close by. Recently i try to port this app to my nexus one but it seems like i have to pop up the message every 300s to enable device to go to discoverable mode. does anyone know how i can suppress that? I'm ok with saying ok for the first time but not every 300s :)

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  • How do I disable system pop-ups in Windows CE 6?

    - by Ben Schoepke
    What do I have to do to disable all system pop-ups in WinCE 6 R2? I read Mike Hall's post about Kiosk mode [1] but that's not going to work for us because we still want the standard graphical Explorer shell. We plan on hiding the taskbar and start menu and clearing icons off the desktop but need an easy way to make sure that no pop-ups of any type will ever show up on top of our app. Thanks, Ben http://blogs.msdn.com/mikehall/archive/2007/06/01/kiosk-mode-for-ce-6-0.aspx

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  • Kernel api's or using api's in the kernel

    - by user513647
    Hello everybody I'd like to know if and how I can access api calls inside the kernel. I need them to preform several integrity checks on a program of mine running in user mode. But I don't know how I can access the api's and funcions required to do so. Does anybody know how to obtain the process id of my user mode proces? and how to access all it's memory to preform the check? Thanks in advance ps: My I'm on a windows xp machine

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  • Flex: convert VideoPlayer.currentTime to string "00:00:00:000"

    - by numediaweb
    Hi there! what about this one: I want to format the currentTime displayed by a videoPlayer component inside flex, something like : 8230.999 to something like 01:59:59:999 which is "hours:minutes:seconds:milliseconds" I trie different sets of codes but they can't get it to work because currentTime is nor a correct miliseconds time as it adds a floating 3 digit point to seconds; so instead of : 2000ms it outputs 2.000 something people like me just can't understand! thanx for any help :) ### UPDATE I still have problem with milliseconds. here's the current MXML: <?xml version="1.0" encoding="utf-8"?> <s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark" xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600"> <fx:Script> <![CDATA[ protected function convert_clickHandler(event:MouseEvent):void { var val:Number = new Number(inPut.text); //inPut.text = 1000.001 //val = val * 1000; outPut.text = timeFormat(val); } public static function timeFormat(value:Number):String { var milliseconds:Number = value % 1000; var seconds:Number = Math.floor((value/1000) % 60); var minutes:Number = Math.floor((value/60000) % 60); var hours:Number = Math.floor((value/3600000) % 24); var s_miliseconds:String = (milliseconds<10 ? "00" : (milliseconds<100 ? "0" : ""))+ String(milliseconds); var s_seconds:String = seconds < 10 ? "0" + String(seconds) : String(seconds); var s_minutes:String = minutes < 10 ? "0" + String(minutes) : String(minutes); var s_hours:String = hours < 10 ? "0" + String(hours) : String(hours); return s_hours + ":" + s_minutes + ":" + s_seconds + '.'+s_miliseconds; // returns 00:00:01.000.0009999999999763531 should return 00:00:01.001 // I still have problem with milliseconds } ]]> </fx:Script> <fx:Declarations> <!-- Place non-visual elements (e.g., services, value objects) here --> </fx:Declarations> <s:TextInput x="240" y="72" id="inPut" text="1000.001"/> <s:TextInput x="240" y="140" id="outPut"/> <s:Button x="274" y="107" label="convert" id="convert" click="convert_clickHandler(event)"/> </s:Application>

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  • Dependency Injection: I don't get where to start!

    - by Andy
    I have several articles about Dependency Injection, and I can see the benefits, especially when it comes to unit testing. The units can me loosely coupled, and mocking of dependencies can be made. The trouble is - I just don't get where to start. Consider this snippet below of (much edited for the purpose of this post) code that I have. I am instantiating a Plc object from the main form, and passing in a communications mode via the Connect method. In it's present form it becomes hard to test, because I can't isolate the Plc from the CommsChannel to unit test it. (Can I?) The class depends on using a CommsChannel object, but I am only passing in a mode that is used to create this channel within the Plc itself. To use dependancy injection, I should really pass in an already created CommsChannel (via an 'ICommsChannel' interface perhaps) to the Connect method, or maybe via the Plc constructor. Is that right? But then that would mean creating the CommsChannel in my main form first, and this doesn't seem right either, because it feels like everything will come back to the base layer of the main form, where everything begins. Somehow it feels like I am missing a crucial piece of the puzzle. Where do you start? You have to create an instance of something somewhere, but I'm struggling to understand where that should be. public class Plc() { public bool Connect(CommsMode commsMode) { bool success = false; // Create new comms channel. this._commsChannel = this.GetCommsChannel(commsMode); // Attempt connection success = this._commsChannel.Connect(); return this._connected; } private CommsChannel GetCommsChannel(CommsMode mode) { CommsChannel channel; switch (mode) { case CommsMode.RS232: channel = new SerialCommsChannel( SerialCommsSettings.Default.ComPort, SerialCommsSettings.Default.BaudRate, SerialCommsSettings.Default.DataBits, SerialCommsSettings.Default.Parity, SerialCommsSettings.Default.StopBits); break; case CommsMode.Tcp: channel = new TcpCommsChannel( TCPCommsSettings.Default.IP_Address, TCPCommsSettings.Default.Port); break; default: // Throw unknown comms channel exception. } return channel; } }

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  • Python/Biomolecular Physics- Trying to code a simple stochastic simulation of a system exhibiting co

    - by user359597
    *edited 6/17/10 I'm trying to understand how to improve my code (make it more pythonic). Also, I'm interested in writing more intuitive 'conditionals' that would describe scenarios that are commonplace in biochemistry. The conditional criteria in the below program is explained in Answer #2, but I am not satisfied with it- it is correct, but isn't obvious and isn't easy to implement for more complicated conditional scenarios. Ideas welcome. Comments/criticisms welcome. First posting experience @ stackoverflow- please comment on etiquette if needed. The code generates a list of values that are the solution to the following exercise: "In a programming language of your choice, implement Gillespie’s First Reaction Algorithm to study the temporal behaviour of the reaction A---B in which the transition from A to B can only take place if another compound, C, is present, and where C dynamically interconverts with D, as modelled in the Petri-net below. Assume that there are 100 molecules of A, 1 of C, and no B or D present at the start of the reaction. Set kAB to 0.1 s-1 and both kCD and kDC to 1.0 s-1. Simulate the behaviour of the system over 100 s." def sim(): # Set the rate constants for all transitions kAB = 0.1 kCD = 1.0 kDC = 1.0 # Set up the initial state A = 100 B = 0 C = 1 D = 0 # Set the start and end times t = 0.0 tEnd = 100.0 print "Time\t", "Transition\t", "A\t", "B\t", "C\t", "D" # Compute the first interval transition, interval = transitionData(A, B, C, D, kAB, kCD, kDC) # Loop until the end time is exceded or no transition can fire any more while t <= tEnd and transition >= 0: print t, '\t', transition, '\t', A, '\t', B, '\t', C, '\t', D t += interval if transition == 0: A -= 1 B += 1 if transition == 1: C -= 1 D += 1 if transition == 2: C += 1 D -= 1 transition, interval = transitionData(A, B, C, D, kAB, kCD, kDC) def transitionData(A, B, C, D, kAB, kCD, kDC): """ Returns nTransition, the number of the firing transition (0: A->B, 1: C->D, 2: D->C), and interval, the interval between the time of the previous transition and that of the current one. """ RAB = kAB * A * C RCD = kCD * C RDC = kDC * D dt = [-1.0, -1.0, -1.0] if RAB > 0.0: dt[0] = -math.log(1.0 - random.random())/RAB if RCD > 0.0: dt[1] = -math.log(1.0 - random.random())/RCD if RDC > 0.0: dt[2] = -math.log(1.0 - random.random())/RDC interval = 1e36 transition = -1 for n in range(len(dt)): if dt[n] > 0.0 and dt[n] < interval: interval = dt[n] transition = n return transition, interval if __name__ == '__main__': sim()

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