Search Results

Search found 21224 results on 849 pages for 'dynamic array'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 72/849 | < Previous Page | 68 69 70 71 72 73 74 75 76 77 78 79  | Next Page >

  • c++ delete[] and array of objects

    - by osgx
    Hello I have allocated and array of Objects Objects *array = new Objects[N]; How should I delete this array? Just delete[] array; or with iterating over array's elements? for(int i=0;i<N;i++) delete array[i]; delete[]; Thanks

    Read the article

  • PHP: Remove the first and last item of the array

    - by phpBOY
    Hi, Suppose I have this array: $array = array('10', '20', '30.30', '40', '50'); Questions What is the fastest/easiest way to remove the first item from the above array? What is the fastest/easiest way to remove the last item from the above array? So the resulting array contains only these values: '20' '30.30' '40'

    Read the article

  • How to find the Biggest and smallest in Int[] Array using c#

    - by karthik
    If the array is as follows, int[] array = new int[] { 7, 4, 1, 8 }; I want to find the Biggest, smallest, second smallest, second biggest If the array is as follows, int[] array = new int[] { 7, 4, 1 }; I want to find the Biggest, smallest, second smallest If the array is as follows, int[] array = new int[] { 7, 4 }; I want to find the Biggest, smallest How can i achieve this programmaticly.

    Read the article

  • ordering array keys?

    - by fayer
    i want to create an array with 2 keys and i want them in following order: $array['higher']; $array['escalate']; how could i accomplish this without creating any value. i want to add values to the array with later on... $array['higher'][] = 'some_value'; $array['escalate'][] = 'some_value'; ...but first i need to create the keys in that order. thanks in advance!

    Read the article

  • Populating a color array with every 8th pixel in an image. C#

    - by Piper
    I have an image that is 512x280 pixels. I want to populate a 64x35 array with every 8th pixel in the matrix. Here is what I have right now: Color[,] imgArray = new Color[b.Width, b.Height]; for (int y = 0; y < 35; y++) { for (int x = 0; x < 64; x++) { imgArray[x, y] = b.GetPixel(x, y); } } But that will get just the top corner of the image. How would I change the loop so it grabs every 8th pixel to fill the array with? edit: I think I may have gotten it. Can someone read this and assure me that it is correct? Color[,] imgArray = new Color[64, 35]; for (int y = 0; y < 280; y+=8) { for (int x = 0; x < 512; x+=8) { imgArray[x, y] = b.GetPixel(x, y); } }

    Read the article

  • What does it mean when you try to print an array or hash using Perl and you get, Array(0xd3888)?

    - by Luke
    What does it mean when you try to print an array or hash and you see the following; Array(0xd3888) or HASH(0xd3978)? EXAMPLE CODE my @data = ( ['1_TEST','1_T','1_TESTER'], ['2_TEST','2_T','2_TESTER'], ['3_TEST','3_T','3_TESTER'], ['4_TEST','4_T','4_TESTER'], ['5_TEST','5_T','5_TESTER'], ['6_TEST','6_T','^_TESTER'] ); foreach my $line (@data) { chomp($line); @random = split(/\|/,$line); print "".$random[0]."".$random[1]."".$random[2]."","\n"; } RESULT ARRAY(0xc1864) ARRAY(0xd384c) ARRAY(0xd3894) ARRAY(0xd38d0) ARRAY(0xd390c) ARRAY(0xd3948)

    Read the article

  • Extracting array with set::class utility

    - by Sabourinov
    Is there a way to extract the array for a specified id with the set::class utiliy? I can't figure out the XPath. I.E. I would like to extract the array where the id = 1 [Document] = Array ( [0] = Array ( [id] = 1 [filename] = 1.txt ) [1] = Array ( [id] = 2 [filename] = 2.txt ) [2] = Array ( [id] = 3 [filename] = 3.txt ) )

    Read the article

  • Are there any empirical studies on the effect of different languages on software quality?

    - by jgre
    The proponents of functional programming languages assert that functional programming makes it easier to reason about code. Those in favor of statically typed languages say that their compilers catch enough errors to make up for the additional complexity of type systems. But everything I read on these topics is based on rational argument, not on empirical data. Are there any empirical studies on what effects the different categories of programming languages have on defect rates or other quality metrics? (The answers to this question seem to indicate that there are no such studies, at least not for the dynamic vs. static debate)

    Read the article

  • Building dynamic OLAP data marts on-the-fly

    - by DrJohn
    At the forthcoming SQLBits conference, I will be presenting a session on how to dynamically build an OLAP data mart on-the-fly. This blog entry is intended to clarify exactly what I mean by an OLAP data mart, why you may need to build them on-the-fly and finally outline the steps needed to build them dynamically. In subsequent blog entries, I will present exactly how to implement some of the techniques involved. What is an OLAP data mart? In data warehousing parlance, a data mart is a subset of the overall corporate data provided to business users to meet specific business needs. Of course, the term does not specify the technology involved, so I coined the term "OLAP data mart" to identify a subset of data which is delivered in the form of an OLAP cube which may be accompanied by the relational database upon which it was built. To clarify, the relational database is specifically create and loaded with the subset of data and then the OLAP cube is built and processed to make the data available to the end-users via standard OLAP client tools. Why build OLAP data marts? Market research companies sell data to their clients to make money. To gain competitive advantage, market research providers like to "add value" to their data by providing systems that enhance analytics, thereby allowing clients to make best use of the data. As such, OLAP cubes have become a standard way of delivering added value to clients. They can be built on-the-fly to hold specific data sets and meet particular needs and then hosted on a secure intranet site for remote access, or shipped to clients' own infrastructure for hosting. Even better, they support a wide range of different tools for analytical purposes, including the ever popular Microsoft Excel. Extension Attributes: The Challenge One of the key challenges in building multiple OLAP data marts based on the same 'template' is handling extension attributes. These are attributes that meet the client's specific reporting needs, but do not form part of the standard template. Now clearly, these extension attributes have to come into the system via additional files and ultimately be added to relational tables so they can end up in the OLAP cube. However, processing these files and filling dynamically altered tables with SSIS is a challenge as SSIS packages tend to break as soon as the database schema changes. There are two approaches to this: (1) dynamically build an SSIS package in memory to match the new database schema using C#, or (2) have the extension attributes provided as name/value pairs so the file's schema does not change and can easily be loaded using SSIS. The problem with the first approach is the complexity of writing an awful lot of complex C# code. The problem of the second approach is that name/value pairs are useless to an OLAP cube; so they have to be pivoted back into a proper relational table somewhere in the data load process WITHOUT breaking SSIS. How this can be done will be part of future blog entry. What is involved in building an OLAP data mart? There are a great many steps involved in building OLAP data marts on-the-fly. The key point is that all the steps must be automated to allow for the production of multiple OLAP data marts per day (i.e. many thousands, each with its own specific data set and attributes). Now most of these steps have a great deal in common with standard data warehouse practices. The key difference is that the databases are all built to order. The only permanent database is the metadata database (shown in orange) which holds all the metadata needed to build everything else (i.e. client orders, configuration information, connection strings, client specific requirements and attributes etc.). The staging database (shown in red) has a short life: it is built, populated and then ripped down as soon as the OLAP Data Mart has been populated. In the diagram below, the OLAP data mart comprises the two blue components: the Data Mart which is a relational database and the OLAP Cube which is an OLAP database implemented using Microsoft Analysis Services (SSAS). The client may receive just the OLAP cube or both components together depending on their reporting requirements.  So, in broad terms the steps required to fulfil a client order are as follows: Step 1: Prepare metadata Create a set of database names unique to the client's order Modify all package connection strings to be used by SSIS to point to new databases and file locations. Step 2: Create relational databases Create the staging and data mart relational databases using dynamic SQL and set the database recovery mode to SIMPLE as we do not need the overhead of logging anything Execute SQL scripts to build all database objects (tables, views, functions and stored procedures) in the two databases Step 3: Load staging database Use SSIS to load all data files into the staging database in a parallel operation Load extension files containing name/value pairs. These will provide client-specific attributes in the OLAP cube. Step 4: Load data mart relational database Load the data from staging into the data mart relational database, again in parallel where possible Allocate surrogate keys and use SSIS to perform surrogate key lookup during the load of fact tables Step 5: Load extension tables & attributes Pivot the extension attributes from their native name/value pairs into proper relational tables Add the extension attributes to the views used by OLAP cube Step 6: Deploy & Process OLAP cube Deploy the OLAP database directly to the server using a C# script task in SSIS Modify the connection string used by the OLAP cube to point to the data mart relational database Modify the cube structure to add the extension attributes to both the data source view and the relevant dimensions Remove any standard attributes that not required Process the OLAP cube Step 7: Backup and drop databases Drop staging database as it is no longer required Backup data mart relational and OLAP database and ship these to the client's infrastructure Drop data mart relational and OLAP database from the build server Mark order complete Start processing the next order, ad infinitum. So my future blog posts and my forthcoming session at the SQLBits conference will all focus on some of the more interesting aspects of building OLAP data marts on-the-fly such as handling the load of extension attributes and how to dynamically alter the structure of an OLAP cube using C#.

    Read the article

  • How does the GPL static vs. dynamic linking rule apply to interpreted languages?

    - by ekolis
    In my understanding, the GPL prohibits static linking from non-GPL code to GPL code, but permits dynamic linking from non-GPL code to GPL code. So which is it when the code in question is not linked at all because the code is written in an interpreted language (e.g. Perl)? It would seem to be too easy to exploit the rule if it was considered dynamic linking, but on the other hand, it would also seem to be impossible to legally reference GPL code from non-GPL code if it was considered static! Compiled languages at least have a distinction between static and dynamic linking, but when all "linking" is just running scripts, it's impossible to tell what the intent is without an explicit license! Or is my understanding of this issue incorrect, rendering the question moot? I've also heard of a "classpath exception" which involves dynamic linking; is that not part of the GPL but instead something that can be added on to it, so dynamic linking is only allowed when the license includes this exception?

    Read the article

  • SQL SERVER – Storing Variable Values in Temporary Array or Temporary List

    - by pinaldave
    SQL Server does not support arrays or a dynamic length storage mechanism like list. Absolutely there are some clever workarounds and few extra-ordinary solutions but everybody can;t come up with such solution. Additionally, sometime the requirements are very simple that doing extraordinary coding is not required. Here is the simple case. Let us say here are the values: a, 10, 20, c, 30, d. Now the requirement is to store them in a array or list. It is very easy to do the same in C# or C. However, there is no quick way to do the same in SQL Server. Every single time when I get such requirement, I create a table variable and store the values in the table variables. Here is the example: For SQL Server 2012: DECLARE @ListofIDs TABLE(IDs VARCHAR(100)); INSERT INTO @ListofIDs VALUES('a'),('10'),('20'),('c'),('30'),('d'); SELECT IDs FROM @ListofIDs; GO When executed above script it will give following resultset. Above script will work in SQL Server 2012 only for SQL Server 2008 and earlier version run following code. DECLARE @ListofIDs TABLE(IDs VARCHAR(100), ID INT IDENTITY(1,1)); INSERT INTO @ListofIDs SELECT 'a' UNION ALL SELECT '10' UNION ALL SELECT '20' UNION ALL SELECT 'c' UNION ALL SELECT '30' UNION ALL SELECT 'd'; SELECT IDs FROM @ListofIDs; GO Now in this case, I have to convert numbers to varchars because I have to store mix datatypes in a single column. Additionally, this quick solution does not give any features of arrays (like inserting values in between as well accessing values using array index). Well, do you ever have to store temporary multiple values in SQL Server – if the count of values are dynamic and datatype is not specified early how will you about storing values which can be used later in the programming. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Scripting Part 1

    - by rbishop
    Dynamic Scripting is a large topic, so let me get a couple of things out of the way first. If you aren't familiar with JavaScript, I can suggest CodeAcademy's JavaScript series. There are also many other websites and books that cover JavaScript from every possible angle.The second thing we need to deal with is JavaScript as a programming language versus a JavaScript environment running in a web browser. Many books, tutorials, and websites completely blur these two together but they are in fact completely separate. What does this really mean in relation to DRM? Since DRM isn't a web browser, there are no document, window, history, screen, or location objects. There are no events like mousedown or click. Trying to call alert('hello!') in DRM will just cause an error. Those concepts are all related to an HTML document (web page) and are part of the Browser Object Model or Document Object Model. DRM has its own object model that exposes DRM-related objects. In practice, feel free to use those sorts of tutorials or practice within your browser; Many of the concepts are directly translatable to writing scripts in DRM. Just don't try to call document.getElementById in your property definition!I think learning by example tends to work the best, so let's try getting a list of all the unique property values for a given node and its children. var uniqueValues = {}; var childEnumerator = node.GetChildEnumerator(); while(childEnumerator.MoveNext()) { var propValue = childEnumerator.GetCurrent().PropValue("Custom.testpropstr1"); print(propValue); if(propValue != null && propValue != '' && !uniqueValues[propValue]) uniqueValues[propValue] = true; } var result = ''; for(var value in uniqueValues){ result += "Found value " + value + ","; } return result;  Now lets break this down piece by piece. var uniqueValues = {}; This declares a variable and initializes it as a new empty Object. You could also have written var uniqueValues = new Object(); Why use an object here? JavaScript objects can also function as a list of keys and we'll use that later to store each property value as a key on the object. var childEnumerator = node.GetChildEnumerator(); while(childEnumerator.MoveNext()) { This gets an enumerator for the node's children. The enumerator allows us to loop through the children one by one. If we wanted to get a filtered list of children, we would instead use ChildrenWith(). When we reach the end of the child list, the enumerator will return false for MoveNext() and that will stop the loop. var propValue = childEnumerator.GetCurrent().PropValue("Custom.testpropstr1"); print(propValue); if(propValue != null && propValue != '' && !uniqueValues[propValue]) uniqueValues[propValue] = true; } This gets the node the enumerator is currently pointing at, then calls PropValue() on it to get the value of a property. We then make sure the prop value isn't null or the empty string, then we make sure the value doesn't already exist as a key. Assuming it doesn't we add it as a key with a value (true in this case because it makes checking for an existing value faster when the value exists). A quick word on the print() function. When viewing the prop grid, running an export, or performing normal DRM operations it does nothing. If you have a lot of print() calls with complicated arguments it can slow your script down slightly, but otherwise has no effect. But when using the script editor, all the output of print() will be shown in the Warnings area. This gives you an extremely useful debugging tool to see what exactly a script is doing. var result = ''; for(var value in uniqueValues){ result += "Found value " + value + ","; } return result; Now we build a string by looping through all the keys in uniqueValues and adding that value to our string. The last step is to simply return the result. Hopefully this small example demonstrates some of the core Dynamic Scripting concepts. Next time, we can try checking for node references in other hierarchies to see if they are using duplicate property values.

    Read the article

  • Is type safety worth the trade-offs?

    - by Prof Plum
    I began coding in in Python primarily where there is no type safety, then moved to C# and Java where there is. I found that I could work a bit more quickly and with less headaches in Python, but then again, my C# and Java apps are at much higher level of complexity so I have never given Python a true stress test I suppose. The Java and C# camps make it sound like without the type safety in place, most people would be running into all sorts of horrible bugs left an right and it would be more trouble than its worth. This is not a language comparison, so please do not address issues like compiled vs interpreted. Is type safety worth the hit to speed of development and flexibilty? WHY? to the people who wanted an example of the opinion that dynamic typing is faster: "Use a dynamically typed language during development. It gives you faster feedback, turn-around time, and development speed." - http://blog.jayway.com/2010/04/14/static-typing-is-the-root-of-all-evil/

    Read the article

  • At what point should data be sent back to server?

    - by whamsicore
    A good example would be the stackexchange "rate" button. When a post is upvoted the arrow changes color immediately. However there is a grace period for one to edit one's vote decision (oops! voted by mistake?). Is the upvote action processed immediately or does is only process after a set time period, or when the user leaves the page? How exactly is this rating processed? What is the standard for handling dynamic page edits (e.g. stackexchange rating, facebook posts?)

    Read the article

  • How to solve linear recurrences involving two functions?

    - by Aditya Bahuguna
    Actually I came across a question in Dynamic Programming where we need to find the number of ways to tile a 2 X N area with tiles of given dimensions.. Here is the problem statement Now after a bit of recurrence solving I came out with these. F(n) = F(n-1) + F(n-2) + 2G(n-1), and G(n) = G(n-1) + F(n-1) I know how to solve LR model where one function is there.For large N as is the case in the above problem we can do the matrix exponentiation and achieve O(k^3log(N)) time where k is the minimum number such that for all km F(n) does not depend on F(n-k). The method of solving linear recurrence with matrix exponentiation as it is given in that blog. Now for the LR involving two functions can anyone suggest an approach feasible enough for large N.

    Read the article

  • Can there be an Environment that Reacts to Weather changes in-game?

    - by The415
    Just to be straightforward, I am completely new to many aspects of coding and am searching for different specs and guidelines to aid me on my journey to crafting a wonderful game in Epic Games' Unreal Engine 4. I had some recent thoughts about the possibility of creating an environment in a game that interacts with weather (Rain, Snow, Storms) Is it possible to make an environment that can simulate weather changes in a game? I wrote notes on this for weeks now. I was thinking that an increase on environments occlusion maps was necessary for creating the effect of rain on windows, as well as making a flowing liquid surface on windows that is only visible in rain. I was also considering the idea of additive bump-maps on meshes for snow, to simulate accumulation. Are these elements dynamic in Unreal 4? Can I implement them?

    Read the article

  • Need to organize words based on their components, any other way aside from brute force?

    - by Lathan
    I'm not sure if this process has a name. I have some words (about 9,000). They are in Japanese, but I'll try to explain this using English words. I want to categorize the words by the components (in English, letters). A B C act bar play This should create: A: play B: bar C: act Now, 'a' appears in all 3 words, but I want to make sure that each category (letter) has at least word. Now, it would make sense to delete a word after it's used, but there are a few cases where 2 letters make up one word and that's each letter's only word--so I'd like to account for that somehow. Is there an approach for solving this aside from brute force? Dynamic programming perhaps? Even a name for this process (if it exists) would be great.

    Read the article

  • PHP - not returning a count number for filled array...

    - by Phil Jackson
    Morning, this is eating me alive so Im hoping it's not something stupid, lol. $arrg = array(); if( str_word_count( $str ) > 1 ) { $input_arr = explode(' ', $str); die(print_r($input_arr)); $count = count($input_arr); die($count); above is part of a function. when i run i get; > Array ( > [0] => luke > [1] => snowden > [2] => create > [3] => develop > [4] => web > [5] => applications > [6] => sites > [7] => alse > [8] => dab > [9] => hand > [10] => design > [11] => love > [12] => helping > [13] => business > [14] => thrive > [15] => latest > [16] => industry > [17] => developer > [18] => act > [19] => designs > [20] => php > [21] => mysql > [22] => jquery > [23] => ajax > [24] => xhtml > [25] => css > [26] => de > [27] => montfont > [28] => award > [29] => advanced > [30] => programming > [31] => taught > [32] => development > [33] => years > [34] => experience > [35] => topic > [36] => fully > [37] => qualified > [38] => electrician > [39] => city > [40] => amp > [41] => guilds > [42] => level ) Which im expecting; run this however and nothing is returned!?!?! $arrg = array(); if( str_word_count( $str ) > 1 ) { $input_arr = explode(' ', $str); //die(print_r($input_arr)); $count = count($input_arr); die($count); can anyone see anything that my eyes cant?? regards, Phil

    Read the article

  • ASp.Net Mvc 1.0 Dynamic Images Returned from Controller taking 154 seconds+ to display in IE8, firef

    - by julian guppy
    I have a curious problem with IE, IIS 6.0 dynamic PNG files and I am baffled as to how to fix.. Snippet from Helper (this returns the URL to the view for requesting the images from my Controller. string url = LinkBuilder.BuildUrlFromExpression(helper.ViewContext.RequestContext, helper.RouteCollection, c = c.FixHeight(ir.Filename, ir.AltText, "FFFFFF")); url = url.Replace("&", "&"); sb.Append(string.Format("<removed id=\"TheImage\" src=\"{0}\" alt=\"\" /", url)+Environment.NewLine); This produces a piece of html as follows:- img id="TheImage" src="/ImgText/FixHeight?sFile=Images%2FUser%2FJulianGuppy%2FMediums%2Fconservatory.jpg&backgroundColour=FFFFFF" alt="" / brackets missing because i cant post an image... even though I dont want to post an image I jsut want to post the markup... sigh Snippet from Controller ImgTextController /// <summary> /// This function fixes the height of the image /// </summary> /// <param name="sFile"></param> /// <param name="alternateText"></param> /// <param name="backgroundColour"></param> /// <returns></returns> [AcceptVerbs(HttpVerbs.Get)] public ActionResult FixHeight(string sFile, string alternateText, string backgroundColour) { #region File if (string.IsNullOrEmpty(sFile)) { return new ImgTextResult(); } // MVC specific change to prepend the new directory if (sFile.IndexOf("Content") == -1) { sFile = "~/Content/" + sFile; } // open the file System.Drawing.Image img; try { img = System.Drawing.Image.FromFile(Server.MapPath(sFile)); } catch { img = null; } // did we fail? if (img == null) { return new ImgTextResult(); } #endregion File #region Width // Sort out the width from the image passed to me Int32 nWidth = img.Width; #endregion Width #region Height Int32 nHeight = img.Height; #endregion Height // What is the ideal height given a width of 2100 this should be 1400. var nIdealHeight = (int)(nWidth / 1.40920096852); // So is the actual height of the image already greater than the ideal height? Int32 nSplit; if (nIdealHeight < nHeight) { // Yes, do nothing, well i need to return the iamge... nSplit = 0; } else { // rob wants to not show the white at the top or bottom, so if we were to crop the image how would be do it // 1. Calculate what the width should be If we dont adjust the heigt var newIdealWidth = (int)(nHeight * 1.40920096852); // 2. This newIdealWidth should be smaller than the existing width... so work out the split on that Int32 newSplit = (nWidth - newIdealWidth) / 2; // 3. Now recrop the image using 0-nHeight as the height (i.e. full height) // but crop the sides so that its the correct aspect ration var newRect = new Rectangle(newSplit, 0, newIdealWidth, nHeight); img = CropImage(img, newRect); nHeight = img.Height; nWidth = img.Width; nSplit = 0; } // No, so I want to place this image on a larger canvas and we do this by Creating a new image to be the size that we want System.Drawing.Image canvas = new Bitmap(nWidth, nIdealHeight, PixelFormat.Format24bppRgb); Graphics g = Graphics.FromImage(canvas); #region Color // Whilst we can set the background colour we shall default to white if (string.IsNullOrEmpty(backgroundColour)) { backgroundColour = "FFFFFF"; } Color bc = ColorTranslator.FromHtml("#" + backgroundColour); #endregion Color // Filling the background (which gives us our broder) Brush backgroundBrush = new SolidBrush(bc); g.FillRectangle(backgroundBrush, -1, -1, nWidth + 1, nIdealHeight + 1); // draw the image at the position var rect = new Rectangle(0, nSplit, nWidth, nHeight); g.DrawImage(img, rect); return new ImgTextResult { Image = canvas, ImageFormat = ImageFormat.Png }; } My ImgTextResult is a class that returns an Action result for me but embedding the image from a memory stream into the response.outputstream. snippet from my ImageResults /// <summary> /// Execute the result /// </summary> /// <param name="context"></param> public override void ExecuteResult(ControllerContext context) { // output context.HttpContext.Response.Clear(); context.HttpContext.Response.ContentType = "image/png"; try { var memStream = new MemoryStream(); Image.Save(memStream, ImageFormat.Png); context.HttpContext.Response.BinaryWrite(memStream.ToArray()); context.HttpContext.Response.Flush(); context.HttpContext.Response.Close(); memStream.Dispose(); Image.Dispose(); } catch (Exception ex) { string a = ex.Message; } } Now all of this works locally and lovely, and indeed all of this works on my production server BUT Only for Firefox, Safari, Chrome (and other browsers) IE has a fit and decides that it either wont display the image or it does display the image after approx 154seconds of waiting..... I have made sure my HTML is XHTML compliant, I have made sure I am getting no Routing errors or crashes in my event log on the server.... Now obviously I have been a muppet and have done something wrong... but what I cant fathom is why in development all works fine, and in production all non IE browsers also work fine, but IE 8 using IIS 6.0 production server is having some kind of problem in returning this PNG and I dont have an error to trace... so what I am looking for is guidance as to how I can debug this problem.

    Read the article

  • Build and migrated to software raid (mdadm) on GPT disk, now can't assemble array

    - by John H
    mdadm, gpt issues, unrecognized partitions. Simplified question: How do I get mdadm to recognize GPT partitions? I have been attempting to convert/copy my Ubuntu 11.10 OS from a single drive to software raid 1. I have done similar in the past, but in this case, I was adding in a drive that has been configured for GPT and I tried to work with that without fully looking into the implications. Currently, I have a non-booting mdadm RAID 1 array of /dev/md127 (the OS assigned that and it keeps picking up). I am booting off of live USB keys, currently System Rescue CD from sysresccd. While gdisk and parted can see all the partitions, most of the OS utilities do not, including mdadm. My main goal is just to make the raid array accessible so I can get pull the data and start fresh (without using GPT). /dev/md127 /dev/sda /dev/sda1 <- GPT type partition /dev/sda1 <- exists within the GPT part, member of md127 /dev/sda2 <- exists within the GPT part, empty /dev/sdb /dev/sdb1 <- GPT type partition /dev/sdb1 <- exists within the GPT part, member of md127 History: POINT A: The original OS was install on sda (actually /dev/sda6). I used a the Ubuntu live usb to add sdb. I got warning from fdisk about GPT so I used gdisk to create a raid partition (sdb1) and mdadm to create a raid1 mirror with a missing drive. I had many issues getting this working (including being unable to get grub to install) but I eventually got it to boot using grub on sda and /dev/md127 off of sdb. So at point A, I had copied my OS from sda6 to md127 on sdb. I then booted into a rescue mode and attempted to get a bootloader onto sdb, which failed. I then discovered my mistake: I had installed the raid onto sdb instead of sdb1, essentially overwriting the sdb1 partition. POINT B: I now had two copies of my data- one on md127/sdb, and one on sda. I destroyed data on sda and created a new GPT table on sda. I then created sda1 for the raid array, and sda2 for a scratch partition. I added sda1 into the raid array and let it rebuild. md127 now covered /dev/sdb and /dev/sda1 as fully active and synced. POINT C: I rebooted onto linux rescue again and was still able to access the raid array. I then removed /dev/sdb from the array and created /dev/sdb1 for the raid. I added sdb1 to the array and let it sync. I was able to mount and access /dev/md127 without issues. Once it completed, both /dev/sda1 and /dev/sdb1 were GPT partitions and actively syncing. POINT D (current): I rebooted again to test if the array would boot and grub failed to load. I booted off of my live thumb drive and found that I can no longer assemble the raid array. mdadm doesn't see the required partitions. -- root@freshdesk /root % uname -a Linux freshdesk 3.0.24-std251-amd64 #2 SMP Sat Mar 17 12:08:55 UTC 2012 x86_64 AMD Athlon(tm) II X4 645 Processor AuthenticAMD GNU/Linux === /proc/partitions and parted look good: root@freshdesk /root % cat /proc/partitions major minor #blocks name 7 0 301788 loop0 8 0 976762584 sda 8 1 732579840 sda1 8 2 244181703 sda2 8 16 732574584 sdb 8 17 732573543 sdb1 8 32 7876607 sdc 8 33 7873349 sdc1 (parted) print all Model: ATA ST31000528AS (scsi) Disk /dev/sda: 1000GB Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 750GB 750GB ext4 2 750GB 1000GB 250GB Linux/Windows data Model: ATA SAMSUNG HD753LJ (scsi) Disk /dev/sdb: 750GB Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 750GB 750GB ext4 Linux RAID raid Model: SanDisk SanDisk Cruzer (scsi) Disk /dev/sdc: 8066MB Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size Type File system Flags 1 31.7kB 8062MB 8062MB primary fat32 boot, lba === # no sda2, and I double the sdb1 is the one shown in parted root@freshdesk /root % blkid /dev/loop0: TYPE="squashfs" /dev/sda1: UUID="75dd6c2d-f0a8-4302-9da4-792cc7d72355" TYPE="ext4" /dev/sdc1: LABEL="PENDRIVE" UUID="1102-3720" TYPE="vfat" /dev/sdb1: UUID="2dd89f15-65bb-ff88-e368-bf24bd0fce41" TYPE="linux_raid_member" root@freshdesk /root % mdadm -E /dev/sda1 mdadm: No md superblock detected on /dev/sda1. # this is probably a result of me attempting to force the array up, putting superblocks on the GPT partition root@freshdesk /root % mdadm -E /dev/sdb1 /dev/sdb1: Magic : a92b4efc Version : 0.90.00 UUID : 2dd89f15:65bbff88:e368bf24:bd0fce41 Creation Time : Fri Mar 30 19:25:30 2012 Raid Level : raid1 Used Dev Size : 732568320 (698.63 GiB 750.15 GB) Array Size : 732568320 (698.63 GiB 750.15 GB) Raid Devices : 2 Total Devices : 2 Preferred Minor : 127 Update Time : Sat Mar 31 12:39:38 2012 State : clean Active Devices : 1 Working Devices : 2 Failed Devices : 1 Spare Devices : 1 Checksum : a7d038b3 - correct Events : 20195 Number Major Minor RaidDevice State this 2 8 17 2 spare /dev/sdb1 0 0 8 1 0 active sync /dev/sda1 1 1 0 0 1 faulty removed 2 2 8 17 2 spare /dev/sdb1 === root@freshdesk /root % mdadm -A /dev/md127 /dev/sda1 /dev/sdb1 mdadm: no recogniseable superblock on /dev/sda1 mdadm: /dev/sda1 has no superblock - assembly aborted root@freshdesk /root % mdadm -A /dev/md127 /dev/sdb1 mdadm: cannot open device /dev/sdb1: Device or resource busy mdadm: /dev/sdb1 has no superblock - assembly aborted

    Read the article

  • Container fix width. Center div dynamic width. want left right divs to fill out remaining width equally

    - by james
    Have Three columns..Combine width of all three is fixed.. 2nd ( center ) column will have dynamic content.. I need left and right column to fill out remaining space ( container width - center column dynamic width )equally. Example: http://jsfiddle.net/htKje/ <div class="container"> <div class="bg"></div> <div>Lorem Ipsum</div> <div class="bg"></div> </div> CSS : .container { width:500px; } .bg {backgrould:#CCC; }

    Read the article

  • How to remove the boundary effects arising due to zero padding in scipy/numpy fft?

    - by Omkar
    I have made a python code to smoothen a given signal using the Weierstrass transform, which is basically the convolution of a normalised gaussian with a signal. The code is as follows: #Importing relevant libraries from __future__ import division from scipy.signal import fftconvolve import numpy as np def smooth_func(sig, x, t= 0.002): N = len(x) x1 = x[-1] x0 = x[0] # defining a new array y which is symmetric around zero, to make the gaussian symmetric. y = np.linspace(-(x1-x0)/2, (x1-x0)/2, N) #gaussian centered around zero. gaus = np.exp(-y**(2)/t) #using fftconvolve to speed up the convolution; gaus.sum() is the normalization constant. return fftconvolve(sig, gaus/gaus.sum(), mode='same') If I run this code for say a step function, it smoothens the corner, but at the boundary it interprets another corner and smoothens that too, as a result giving unnecessary behaviour at the boundary. I explain this with a figure shown in the link below. Boundary effects This problem does not arise if we directly integrate to find convolution. Hence the problem is not in Weierstrass transform, and hence the problem is in the fftconvolve function of scipy. To understand why this problem arises we first need to understand the working of fftconvolve in scipy. The fftconvolve function basically uses the convolution theorem to speed up the computation. In short it says: convolution(int1,int2)=ifft(fft(int1)*fft(int2)) If we directly apply this theorem we dont get the desired result. To get the desired result we need to take the fft on a array double the size of max(int1,int2). But this leads to the undesired boundary effects. This is because in the fft code, if size(int) is greater than the size(over which to take fft) it zero pads the input and then takes the fft. This zero padding is exactly what is responsible for the undesired boundary effects. Can you suggest a way to remove this boundary effects? I have tried to remove it by a simple trick. After smoothening the function I am compairing the value of the smoothened signal with the original signal near the boundaries and if they dont match I replace the value of the smoothened func with the input signal at that point. It is as follows: i = 0 eps=1e-3 while abs(smooth[i]-sig[i])> eps: #compairing the signals on the left boundary smooth[i] = sig[i] i = i + 1 j = -1 while abs(smooth[j]-sig[j])> eps: # compairing on the right boundary. smooth[j] = sig[j] j = j - 1 There is a problem with this method, because of using an epsilon there are small jumps in the smoothened function, as shown below: jumps in the smooth func Can there be any changes made in the above method to solve this boundary problem?

    Read the article

  • empty() not a valid callback?

    - by user151841
    I'm trying to use empty() in array mapping in php. I'm getting errors that it's not a valid callback. $ cat test.php <? $arrays = array( 'arrEmpty' => array( '','','' ), ); foreach ( $arrays as $key => $array ) { echo $key . "\n"; echo array_reduce( $array, "empty" ); var_dump( array_map("empty", $array) ); echo "\n\n"; } $ php test.php arrEmpty Warning: array_reduce(): The second argument, 'empty', should be a valid callback in /var/www/authentication_class/test.php on line 12 Warning: array_map(): The first argument, 'empty', should be either NULL or a valid callback in /var/www/authentication_class/test.php on line 13 NULL Shouldn't this work? Long story: I'm trying to be (too?) clever and checking that all array values are not empty strings.

    Read the article

  • How to solve JavaScript origin problem with an application and static file server

    - by recipriversexclusion
    In a system that I'm building I want to serve Static files (static HTML pages and a lot of images), and Dynamic XML generated by my servlet. The dynamic XML is generated from my database (through Hibernate) and I use Restlets to serve it in response to API calls. I want to create a static file server (e.g. Apache) so that this does not interfere with the dynamic server traffic. Currently both servers need to run on the same machine. I've never done something like this before and this is where I'm stuck: The static HTML pages contain JavaScript that makes API calls to the dynamic server. However, since the two servers operate on different ports, I get stuck with the same origin problem. How can this be solved? As a bonus, if you can point me to any resources that explain how to create such a static/dynamic content serving system, I'll be happy. Thanks!

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 68 69 70 71 72 73 74 75 76 77 78 79  | Next Page >