Search Results

Search found 16174 results on 647 pages for 'disk space'.

Page 563/647 | < Previous Page | 559 560 561 562 563 564 565 566 567 568 569 570  | Next Page >

  • What am I doing wrong with HttpResponse content and headers when downloading a file?

    - by Slauma
    I want to download a PDF file from a SQL Server database which is stored in a binary column. There is a LinkButton on an aspx page. The event handler of this button looks like this: protected void LinkButtonDownload(object sender, EventArgs e) { ... byte[] aByteArray; // Read binary data from database into this ByteArray // aByteArray has the size: 55406 byte Response.ClearHeaders(); Response.ClearContent(); Response.BufferOutput = true; Response.AddHeader("Content-Disposition", "attachment; filename=" + "12345.pdf"); Response.ContentType = "application/pdf"; using (BinaryWriter aWriter = new BinaryWriter(Response.OutputStream)) { aWriter.Write(aByteArray, 0, aByteArray.Length); } } A "File Open/Save dialog" is offered in my browser. When I store this file "12345.pdf" to disk, the file has a size of 71523 Byte. The additional 16kB at the end of the PDF file are the HTML code of my page (as I can see when I view the file in an editor). I am confused because I was believing that ClearContent and ClearHeaders would ensure that the page content is not sent together with the file content. What am I doing wrong here? Thanks for help!

    Read the article

  • jquery/javascript - image resize to fit screen

    - by alberto
    not an expert programmer. i created this code to resize photos/images to fit the screen, considering the space available for the nav bar. the script happens on load of image, and on click of the navigation. is it a good piece of code, or could it be done better? any browser issues? in the html: $(document).ready(function(){ $("#photo").load(function(){ resize(); }); $(".navigation img").click(function(){ var imgPath = $(this).attr("src"); $("#photo").attr({ src: imgPath }); resize(); return false; }); }); while this is my function resize: resize = function() { var borderVt=150; //value based on css style. bottom bar + padding of photoContain var borderHz=40; //value based on css style photoContain padding $("#photo").css("width", "auto").css("height", "auto"); // Remove existing CSS $("#photo").removeAttr("width").removeAttr("height"); // Remove HTML attributes var origSizeW = $("#photo").width(); var origSizeH = $("#photo").height(); var ratioVt=(origSizeW/origSizeH); var ratioHz=(origSizeH/origSizeW); var winW = $(window).width(); var winH = $(window).height(); var screenSizeW=Math.round(winW-borderHz); var screenSizeH=Math.round(winH-borderVt); if (origSizeW>=origSizeH){ var newHeight = Math.round(screenSizeW*ratioHz); if (newHeight <= screenSizeH){ $("#photo").css("width", screenSizeW); // Set new width $("#photo").css("height", newHeight); } else{ $("#photo").css("height", screenSizeH); } } else{ $("#photo").css("height", screenSizeH); // Set new height } };

    Read the article

  • Show cue banner for wpf ComboBox with grouping

    - by Adam Duston
    I have a ComboBox in my WPF form: <ComboBox Margin="75,0,15,102" Name="videoFormatCombo" Height="23" VerticalAlignment="Bottom" DataContext="{StaticResource GroupedVideoFormats}" ItemsSource="{Binding}" ItemTemplate="{StaticResource VideoFormatTemplate}"> <ComboBox.GroupStyle> <GroupStyle HeaderTemplate="{StaticResource GroupHeader}"/> </ComboBox.GroupStyle> </ComboBox> As you might be able to guess, GroupedVideoFormats is a CollectionViewSource with grouping. I need to get a cue banner to display for this ComboBox. I've attempted the solution that is (very verbosely) outlined in this blog post, but it will not work for a ComboBox with grouped data. The two solutions outlined in superfluousprefixhttp://stackoverflow.com/questions/2548757/how-can-the-blank-space-in-a-c-combobox-be-filled-as-a-hint-for-the-user are for Windows Forms ComboBoxes only, and won't work with WPF. If it would help to see all the original source, this particular form is on github: superfluousprefixhttp://github.com/8planes/mirovideoconverter/blob/master/MSWindows/Windows/FileSelect.xaml . It's an open-source project, so the entire project is on github: superfluousprefixhttp://github.com/8planes/mirovideoconverter/tree/master/MSWindows . Thank you for any advice! Adam P.S. stackoverflow wouldn't let me make more than one anchor tag in my post, hence the long urls with the superfluous prefix. Sorry!

    Read the article

  • Tracing spoofed mobile phone numbers

    - by RaDeuX
    I am being harassed by some prank caller that is spoofing his/her number neither T-Mobile nor the police can do anything about it. I have been told from one of my friends that if I set up an Asterisk server, I can accomplish the tracing of the prank caller. I am hardly knowledgeable in terms of networking, so a lot of what they told me was filled with jargon I couldn't really understand. But first things first, I downloaded Asterisk 1.5.0 and was finally able to install it (had issues with partitioning... In the end I just had Asterisk hog the entire HDD space). I tried out Asterisk, and it was slightly complicated for me so I decided to install trixbox 2.8.0.4 instead. It looks very similar to Asterisk... I'm not entirely sure what to do from here. I know I have to get the server up and running, but do I need a PBX card or something to accomplish what I'm trying to do? I'm running trixbox on a laptop to minimize electricity usage. Also, will I have to open any ports for the server? I have limited administrative permissions because of my father who is very uncomfortable with opening ports.

    Read the article

  • [Doxygen] How to documenting global dependencies for functions?

    - by Thomas Matthews
    I've got some C code from a 3rd party vendor (for an embedded platform) that uses global variables (for speed & space optimizations). I'm documenting the code, converting to Doxygen format. How do I put a note in the function documentation that the function requires on global variables and functions? Doxygen has special commands for annotating parameters and return values as describe here: Doxygen Special Commands. I did not see any commands for global variables. Example C code: extern unsigned char data_buffer[]; //!< Global variable. /*! Returns the next available data byte. * \return Next data byte. */ unsigned char Get_Byte(void) { static unsigned int index = 0; return data_buffer[index++]; //!< Uses global variable. } In the above code, I would like to add Doxygen comments that the function depends on the global variable data_buffer.

    Read the article

  • Appending a child in Cake

    - by pg
    I'm using cake & have a web form for entering URLs to go into my db. There will be one input space (url1) and below that a link that says "add another URL" which, when clicked, generates a new form (url2) and reuses the "add another URL". So it would be like: echo $form->input('name'); echo $form->input('id'); echo $form->input('url1'); echo $form->input('weight1'); echo '<a href="XXX">add another URL</a>'; and then, if XXX is clicked it would be like this: echo $form->input('name'); echo $form->input('id'); echo $form->input('url1'); echo $form->input('weight1'); echo $form->input('url2'); echo $form->input('weight2'); echo '<a href="XXX">add another URL</a>'; Is there a jquery script I can use to do this or does cake have something built in?

    Read the article

  • Convert a Unit Vector to a Quaternion

    - by Hmm
    So I'm very new to quaternions, but I understand the basics of how to manipulate stuff with them. What I'm currently trying to do is compare a known quaternion to two absolute points in space. I'm hoping what I can do is simply convert the points into a second quaternion, giving me an easy way to compare the two. What I've done so far is to turn the two points into a unit vector. From there I was hoping I could directly plug in the i j k into the imaginary portion of the quaternion with a scalar of zero. From there I could multiply one quaternion by the other's conjugate, resulting in a third quaternion. This third quaternion could be converted into an axis angle, giving me the degree by which the original two quaternions differ by. Is this thought process correct? So it should just be [ 0 i j k ]. I may need to normalize the quaternion afterwards, but I'm not sure about that. I have a bad feeling that it's not a direct mapping from a vector to a quaternion. I tried looking at converting the unit vector to an axis angle, but I'm not sure this would work, since I don't know what angle to give as an input.

    Read the article

  • How can I change the CSS visibility style for elements that are not on the screen?

    - by RenderIn
    I have a lot of data being placed into a <DIV> with the overflow: auto style. Firefox handles this gracefully but IE becomes very sluggish both when scrolling the div and when executing any Javascript on the page. At first I thought IE just couldn't handle that much data in its DOM, but then I did a simple test where I applied the visibility: hidden style to every element past the first 100. They still take up space and cause the scrollbars to appear. IE no longer had a problem with the data when I did this. So, I'd like to have a "smart" div that hides all the nested div elements which are not currently visible on the screen. Is there a simple solution to this or will I need to have an infinite loop which calculates the location of the scrollbar? If not, is there a particular event that I can hook into where I could do this? Is there a jQuery selector or plugin that will allow me to select all elements not currently visible on the screen?

    Read the article

  • What is the general feeling about reflection extensions in std::type_info?

    - by Evan Teran
    I've noticed that reflection is one feature that developers from other languages find very lacking in c++. For certain applications I can really see why! It is so much easier to write things like an IDE's auto-complete if you had reflection. And certainly serialization APIs would be a world easier if we had it. On the other side, one of the main tenets of c++ is don't pay for what you don't use. Which makes complete sense. That's something I love about c++. But it occurred to me there could be a compromise. Why don't compilers add extensions to the std::type_info structure? There would be no runtime overhead. The binary could end up being larger, but this could be a simple compiler switch to enable/disable and to be honest, if you are really concerned about the space savings, you'll likely disable exceptions and RTTI anyway. Some people cite issues with templates, but the compiler happily generates std::type_info structures for template types already. I can imagine a g++ switch like -fenable-typeinfo-reflection which could become very popular (and mainstream libs like boost/Qt/etc could easily have a check to generate code which uses it if there, in which case the end user would benefit with no more cost than flipping a switch). I don't find this unreasonable since large portable libraries like this already depend on compiler extensions. So why isn't this more common? I imagine that I'm missing something, what are the technical issues with this?

    Read the article

  • Turing Machine & Modern Computer

    - by smwikipedia
    I heard a lot that modern computers are based on Turing machine. I'd like to share my understanding and hear your comments. I think the computer is a big general-purpose Turing machine. Each program we write is a small specific-purpose Turing machine. The classical Turing machine do its job based on the input and its current state inside and so do our programs. Let's take a running program (a process) as an example. We know that in the process's address space, there's areas for stack, heap, and code. A classical Turing machine doesn't have the ability to remember many things, so we borrow the concept of stack from the push-down automaton. The heap and stack areas contains the state of our specific-purpose Turing machine (our program). The code area represents the logic of this small Turing machine. And various I/O devices supply input to this Turing machine. The above is my naive understanding about the working paradigm of modern computer. I couln't wait to hear your comments. Thanks very much.

    Read the article

  • What is the name of this geometrical function?

    - by Spike
    In a two dimentional integer space, you have two points, A and B. This function returns an enumeration of the points in the quadrilateral subset bounded by A and B. A = {1,1} B = {2,3} Fn(A,B) = {{1,1},{1,2},{1,3},{2,1},{2,2},{2,3}} I can implement it in a few lines of LINQ. private void UnknownFunction(Point to, Point from, List<Point> list) { var vectorX = Enumerable.Range(Math.Min(to.X, from.X), Math.Abs(to.X - from.Y) + 1); var vectorY = Enumerable.Range(Math.Min(to.Y, from.Y), Math.Abs(to.Y - from.Y) + 1); foreach (var x in vectorX) foreach (var y in vectorY) list.Add(new Point(x, y)); } I'm fairly sure that this is a standard mathematical operation, but I can't think what it is. Feel free to tell me that it's one line of code in your language of choice. Or to give me a cunning implementation with lambdas or some such. But mostly I just want to know what it's called. It's driving me nuts. It feels a little like a convolution, but it's been too long since I was at school for me to be sure.

    Read the article

  • Syncing two separate structures to the same master data

    - by Mike Burton
    I've got multiple structures to maintain in my application. All link to the same records, and one of them could be considered the "master" in that it reflects actual relationships held in files on disk. The other structures are used to "call out" elements of the main design for purchase and work orders. I'm struggling to come up with a pattern that deals appropriately with changes to the master data. As an example, the following trees might refer to the same data: A |_ B |_ C |_ D |_ E |_ B |_ C |_ D A |_ B E C |_ D A |_ B C D E These secondary structures follow internal rules, but their overall structure is usually user-determined. In all cases (including the master), any element can be used in multiple locations and in multiple trees. When I add a child to any element in the tree, I want to either automatically build the secondary structure for each instance of the "master" element or at least advertise the situation to the user and allow them to manually generate the data required for the secondary trees. Is there any pattern which might apply to this situation? I've been treating it as a view problem, but it turns out to be more complicated than that when you look at the initial generation of the data.

    Read the article

  • c# web extracting programming, which libraries, examples samples please

    - by user287745
    I have just started programming and have made a few small applications in C and C#. My understanding is that programming for web and thing related to web is nowadays a very easy task. Please note this is for personnel learning, not for rent a coder or any money making. An application which can run on any Windows platform even Windows 98. The application should start automatically at a scheduled time and do the following. Connect to a site which displays stock prices summary (high low current open). Capture the data (excluding the other things in the site.) And save it to disk (an SQL database) Please note:- Internet connection is assumed to be there always. Do not want to know how to make database schema or database. The stock exchange has no law prohibiting the use of the data provided on its site, but I do not want to mention the name in case I am wrong, but it's for personal private use only. The data of summary of pricing is arranged in a table such that when copied pasted to MS Excel it automatically forms a table. need steps guidance please, examples, lbraries

    Read the article

  • Converting non-delimited text into name/value pairs in Delphi

    - by robsoft
    I've got a text file that arrives at my application as many lines of the following form: <row amount="192.00" store="10" transaction_date="2009-10-22T12:08:49.640" comp_name="blah " comp_ref="C65551253E7A4589A54D7CCD468D8AFA" name="Accrington "/> and I'd like to turn this 'row' into a series of name/value pairs in a given TStringList (there could be dozens of these <row>s in the file, so eventually I will want to iterate through the file breaking each row into name/value pairs in turn). The problem I've got is that the data isn't obviously delimited (technically, I suppose it's space delimited). Now if it wasn't for the fact that some of the values contain leading or trailing spaces, I could probably make a few reasonable assumptions and code something to break a row up based on spaces. But as the values themselves may or may not contain spaces, I don't see an obvious way to do this. Delphi' TStringList.CommaText doesn't help, and I've tried playing around with Delimiter but I get caught-out by the spaces inside the values each time. Does anyone have a clever Delphi technique for turning the sample above into something resembling this? ; amount="192.00" store="10" transaction_date="2009-10-22T12:08:49.640" comp_name="blah " comp_ref="C65551253E7A4589A54D7CCD468D8AFA" name="Accrington " Unfortunately, as is usually the case with this kind of thing, I don't have any control over the format of the data to begin with - I can't go back and 'make' it comma delimited at source, for instance. Although I guess I could probably write some code to turn it into comma delimited - would rather find a nice way to work with what I have though. This would be in Delphi 2007, if it makes any difference.

    Read the article

  • How select the rest of the word in incremental search in Eclipse?

    - by arberg
    When in incremental search mode in Eclipse, is there a way to select the rest of the word? For example, suppose I want to find the word “handleReservationGranted”. I type Ctrl-f to enter incremental search mode, and start typing the letters “han”. Now suppose I have found the beginning of “handleReservationGranted”. In my search box I have “han”, but I would now like to be able to select the rest of the word, so that the search box contains “handleReservationGranted” instead of “han”. In Xemacs, I can type Ctrl-s, type “han”, and then type Ctrl-w. Now my search term is “handleReservationGranted”, and not “han”. So now if I press Ctrl-s, I find the next occurrence of “handleReservationGranted”. I frequently prefer the incremental search over the search dialog, as the search dialog takes too much space on my screen, and most annoying it frequently hides the found matches. I am using Eclipse Galileo (3.5.2). Ctrl-Shift-L gives me the list of possible shortcuts in the given context, but none seems to fit what I'm looking for.

    Read the article

  • Why is cell phone software is still so primitive?

    - by Tomislav Nakic-Alfirevic
    I don't do mobile development, but it strikes me as odd that features like this aren't available by default on most phones: full text search: searches all address book contents, messages, anything else being a plus better call management: e.g. a rotating audio call log, meaning you always have the last N calls recorded for your listening pleasure later (your little girl just said her first "da-da" while you were on a business trip, you had a telephone job interview, you received complex instructions to do something etc.) bluetooth remote control (like e.g. anyRemote, but available by default on a bluetooth phone) no multitasking capabilities worth mentioning and in general no e.g. weekly software updates, making the phone much more usable (even if it had to be done over USB, rather than over the network). I'm sure I was dumbfounded by the lack or design of other features as well, but they don't come to mind right now. To clarify, I'm not talking about smartphones here: my plain, 2-year old phone has a CPU an order of magnitude faster than my first PC, about as much storage space and it's ridiculous how bad (slow, unwieldy) the software is and it's not one phone or one manufacturer. What keeps the (to me) obvious software functionality vacuum on a capable hardware platform from being filled up?

    Read the article

  • php & mySQL: Storing doc, xls, zip, etc. with limited access and archiving

    - by Devner
    Hi all, In my application, I have a provision for users to upload files like doc, xls, zip, etc. I would like to know how to store these files on my website and have only restricted people access it. I may have a group of people and let only these group access those uploaded files. I know that some may try to just copy the link to the document or the file and pass it to another (non-permitted) user and they can download it. So how can I prevent it? How can I check if the request to download the file was made by a legitimate user who has access to the file? The usernames of the group members are stored in the database along with the document name and location in the database so they can access it. But how do I prevent non-permitted users from being able to access that confidential data in all ways? With the above in mind, how do I store these documents? Do I store the documents in a blob column in the Database or just just let user upload to a folder and merely store the path to the file in the database? The security of the documents is of utmost importance. So any procedure that could facilitate this feature would definitely help. I am not into Object Oriented programming so if you have a simpler code that you would like to share with me, I would greatly appreciate it. Also how do I archive documents that are old? Like say there are documents that are 1 year old and I want to conserve my website space by archiving them but still make them available to the user when they need it. How do I go about this? Thank you.

    Read the article

  • Convert rank-per-candidate format to OpenSTV BLT format

    - by kibibu
    I recently gathered, using a questionnaire, a set of opinions on the importance of various software components. Figuring that some form of Condorcet voting method would be the best way to obtain an overall rank, I opted to use OpenSTV to analyze it. My data is in tabular format, space delimited, and looks more or less like: A B C D E F G # Candidates 5 2 4 3 7 6 1 # First ballot. G is ranked first, and E is ranked 7th 4 2 6 5 1 7 3 # Second ballot etc In this format, the number indicates the rank and the sequence order indicates the candidate. Each "candidate" has a rank (required) from 1 to 7, where a 1 means most important and a 7 means least important. No duplicates are allowed. This format struck me as the most natural way to represent the output, being a direct representation of the ballot format. The OpenSTV/BLT format uses a different method of representing the same info, conceptually as follows: G B D C A F E # Again, G is ranked first and E is ranked 7th E B G A D C F # etc The actual numeric file format uses the (1-based) index of the candidate, rather than the label, and so is more like: 7 2 4 3 1 6 5 # Same ballots as before. 5 2 7 1 4 3 6 # A -> 1, G -> 7 In this format, the number indicates the candidate, and the sequence order indicates the rank. The actual, real, BLT format also includes a leading weight and a following zero to indicate the end of each ballot, which I don't care too much about for this. My question is, what is the most elegant way to convert from the first format to the (numeric) second?

    Read the article

  • Would it be possible to have a UTF-8-like encoding limited to 3 bytes per character?

    - by dan04
    UTF-8 requires 4 bytes to represent characters outside the BMP. That's not bad; it's no worse than UTF-16 or UTF-32. But it's not optimal (in terms of storage space). There are 13 bytes (C0-C1 and F5-FF) that are never used. And multi-byte sequences that are not used such as the ones corresponding to "overlong" encodings. If these had been available to encode characters, then more of them could have been represented by 2-byte or 3-byte sequences (of course, at the expense of making the implementation more complex). Would it be possible to represent all 1,114,112 Unicode code points by a UTF-8-like encoding with at most 3 bytes per character? If not, what is the maximum number of characters such an encoding could represent? By "UTF-8-like", I mean, at minimum: The bytes 0x00-0x7F are reserved for ASCII characters. Byte-oriented find / index functions work correctly. You can't find a false positive by starting in the middle of a character like you can in Shift-JIS.

    Read the article

  • % style macros not supported in some C++/CLI project property pages under VS2010?

    - by Dave Foster
    We're currently evaluating VS2010 and have upgraded our VS2008 C++/CLI project to the new .vcxproj format. I've noticed that a certain property we had set in the project settings did not get translated properly. Under Configuration Properties - Managed Resources - Resource Logical Name, we used to have (in VS2008) the setting: $(IntDir)\$(RootNamespace).$(InputName).resources which indicated that all .resx files were to compile into OurLib.SomeForm.resources inside of the assembly. (the Debug portion is dropped when assembled) According to MSDN, the $(InputName) macro no longer exists and should be replaced with %(Filename). However, when translating the above line to swap those macros, it does not seem to ever expand. The second .resx file it tries to compile, I get a "LINK : fatal error LNK1316: duplicate managed resource name 'Debug\OurLib.%(Filename).resources". This indicates to me that the % style macros are not being expanded here, at least in this specific property. If we don't set anything in that property, the default behavior seems to be to add the subdirectory as a prefix, such as: OurLib.Forms.SomeForm.resources where Forms is the subdir of our project that the .resx file lives. This only occurs when the .resx file is in an immediate subdirectory of the project being built. If a .resx file exists somewhere else on disk (aka ..\OtherLib\Forms\SomeForm2.resx) this prefix is NOT added. This is causing an issue with loading form resources, as it does not account for this possible prefix, even though we are using the standard Forms Designer method of getting at resources: System::ComponentModel::ComponentResourceManager^ resources = (gcnew System::ComponentModel::ComponentResourceManager(SomeForm::typeid)); and do not specify the .resources file by name. The issue I've just described may not be the same as the original question, but if I were to fix the Resource Logical Name issue I think this would all go away. Does anyone have any information about these % macros and where they are allowed to be used?

    Read the article

  • Any HTTP proxies with explicit, configurable support for request/response buffering and delayed conn

    - by Carlos Carrasco
    When dealing with mobile clients it is very common to have multisecond delays during the transmission of HTTP requests. If you are serving pages or services out of a prefork Apache the child processes will be tied up for seconds serving a single mobile client, even if your app server logic is done in 5ms. I am looking for a HTTP server, balancer or proxy server that supports the following: A request arrives to the proxy. The proxy starts buffering in RAM or in disk the request, including headers and POST/PUT bodies. The proxy DOES NOT open a connection to the backend server. This is probably the most important part. The proxy server stops buffering the request when: A size limit has been reached (say, 4KB), or The request has been received completely, headers and body Only now, with (part of) the request in memory, a connection is opened to the backend and the request is relayed. The backend sends back the response. Again the proxy server starts buffering it immediately (up to a more generous size, say 64KB.) Since the proxy has a big enough buffer the backend response is stored completely in the proxy server in a matter of miliseconds, and the backend process/thread is free to process more requests. The backend connection is immediately closed. The proxy sends back the response to the mobile client, as fast or as slow as it is capable of, without having a connection to the backend tying up resources. I am fairly sure you can do 4-6 with Squid, and nginx appears to support 1-3 (and looks like fairly unique in this respect). My question is: is there any proxy server that empathizes these buffering and not-opening-connections-until-ready capabilities? Maybe there is just a bit of Apache config-fu that makes this buffering behaviour trivial? Any of them that it is not a dinosaur like Squid and that supports a lean single-process, asynchronous, event-based execution model? (Siderant: I would be using nginx but it doesn't support chunked POST bodies, making it useless for serving stuff to mobile clients. Yes cheap 50$ handsets love chunked POSTs... sigh)

    Read the article

  • CSS: Horizontal scrolling with overflow-x

    - by ams
    Hello fellow programmers, I was wondering if there still isn't a good way to get a div to stretch and scroll horizontally, according to the images inside. -After all, it is 2011 now! The mega-width does the trick, but leaves an empty mega-space if not filled with images. If filled too much, images don't display. Same for the jQuery. The situation below is the best I can do after hours of Googling, but it isn't reliable enough. Thanks for your time. Ams * { margin:0; padding:0; } #one { width:200px; height:250px; overflow-x:auto; overflow-y:hidden; } #two { width:10000em; } #two img { float:left; } $(document).ready(function(){ var total=0; $(".calc").each(function(){ total += $(this).outerWidth(true); }); $("#two").css('width',total); alert(total); }); <div id="one"> <div id="two"> <img src="images/testimage3.jpg" width="480" height="192" class="calc"> <img src="images/testimage3.jpg" width="480" height="192" class="calc"> <img src="images/testimage3.jpg" width="480" height="192" class="calc"> <img src="images/testimage3.jpg" width="480" height="192" class="calc"> </div> </div>

    Read the article

  • Discover periodic patterns in a large data-set

    - by Miner
    I have a large sequence of tuples on disk in the form (t1, k1) (t2, k2) ... (tn, kn) ti is a monotonically increasing timestamp and ki is a key (assume a fixed length string if needed). Neither ti nor ki are guaranteed to be unique. However, the number of unique tis and kis is huge (millions). n itself is very large (100 Million+) and the size of k (approx 500 bytes) makes it impossible to store everything in memory. I would like to find out periodic occurrences of keys in this sequence. For example, if I have the sequence (1, a) (2, b) (3, c) (4, b) (5, a) (6, b) (7, d) (8, b) (9, a) (10, b) The algorithm should emit (a, 4) and (b, 2). That is a occurs with a period of 4 and b occurs with a period of 2. If I build a hash of all keys and store the average of the difference between consecutive timestamps of each key and a std deviation of the same, I might be able to make a pass, and report only the ones that have an acceptable std deviation(ideally, 0). However, it requires one bucket per unique key, whereas in practice, I might have very few really periodic patterns. Any better ways?

    Read the article

  • How can I randomly iterate through a large Range?

    - by void
    I would like to randomly iterate through a range. Each value will be visited only once and all values will eventually be visited. For example: class Array def shuffle ret = dup j = length i = 0 while j > 1 r = i + rand(j) ret[i], ret[r] = ret[r], ret[i] i += 1 j -= 1 end ret end end (0..9).to_a.shuffle.each{|x| f(x)} where f(x) is some function that operates on each value. A Fisher-Yates shuffle is used to efficiently provide random ordering. My problem is that shuffle needs to operate on an array, which is not cool because I am working with astronomically large numbers. Ruby will quickly consume a large amount of RAM trying to create a monstrous array. Imagine replacing (0..9) with (0..99**99). This is also why the following code will not work: tried = {} # store previous attempts bigint = 99**99 bigint.times { x = rand(bigint) redo if tried[x] tried[x] = true f(x) # some function } This code is very naive and quickly runs out of memory as tried obtains more entries. What sort of algorithm can accomplish what I am trying to do? [Edit1]: Why do I want to do this? I'm trying to exhaust the search space of a hash algorithm for a N-length input string looking for partial collisions. Each number I generate is equivalent to a unique input string, entropy and all. Basically, I'm "counting" using a custom alphabet. [Edit2]: This means that f(x) in the above examples is a method that generates a hash and compares it to a constant, target hash for partial collisions. I do not need to store the value of x after I call f(x) so memory should remain constant over time. [Edit3/4/5/6]: Further clarification/fixes.

    Read the article

  • How to read a string one letter at a time in python

    - by dan
    I need to convert a string inputed by a user into morse code. The way our professor wants us to do this is to read from a morseCode.txt file, seperate the letters from the morseCode into two lists, then convert each letter to morse code (inserting a new line when there is a space). I have the beginning. What it does is reads the morseCode.txt file and seperates the letters into a list [A, B, ... Z] and the codes into a list ['– – . . – –\n', '. – . – . –\n'...]. We haven't learned "sets" yet, so I can't use that. How would I then take the string that they inputed, go through letter by letter, and convert it to morse code? I'm a bit caught up. Here's what I have right now (not much at all...) morseCodeFile = open('morseCode.txt', 'r') letterList = [] codeList = [] line = morseCodeFile.readline() while line != '': letterList.append(line[0]) codeList.append(line[2:]) line = morseCodeFile.readline() morseCodeFile.close() userInput = input("Enter a string to be converted to morse code or press <enter> to quit ")

    Read the article

< Previous Page | 559 560 561 562 563 564 565 566 567 568 569 570  | Next Page >