Search Results

Search found 3311 results on 133 pages for 'computing theory'.

Page 101/133 | < Previous Page | 97 98 99 100 101 102 103 104 105 106 107 108  | Next Page >

• Why is only one Excel spreadsheet crippled, but others are fine?

  - by Dallas

  I have an inherited spreadsheet that I really don't want to rebuild at the moment. It's a simple small workbook that is small (< 200 rows that don't even reach to AA) and does nothing more than calculate some totals within the same worksheets. No macros, no external data sources, nothing beyond basic formatting of dates, numbers and strings. I see importing data from CSV/text has created many many workbook connections over time, but even if I delete them all (there were hundreds) it makes no difference in performance. Even clicking to simply change focus from cell to cell takes 10+ seconds, adorned by the spinning cursor and (Not Responding) appending to the title bar and the application locking up. The program seems to "recover" every time, but efficiency of editing this file is obviously seriously handicapped. All other files seem fine in Excel, and other programs have no apparent performance issues. I see Excel is chewing up CPU but I'm not sure how to narrow down what process or service is "clashing" with Excel. I tried the same file on other computers and performance is fine. If I turn off all start-up services and run only Excel, performance is restored... until I start using other programs and then it bogs down again. At this point, I would entertain almost any idea, theory or suggestion that helps pinpoint, solve or work around the issue.

  Read the article

• CPU not working on a specific motherboard

  - by Shaman

  I'm making a computer for someone and I met a weird problem. The CPU that I have doesn't work on this motherboard. The CPU is an Intel Pentium D 925 and the motherboard is an ECS G41T-M6, which in theory should work together. The only thing reused is the power source(400W). When I start the computer, the fans start, and that's it. The BIOS doesn't boot. I tried my own power source (600W Corsair) and nothing. Removed the RAM, no warning. In desperation I tried the last thing, swaped my own CPU with this one (Core2Duo E7200). Lo and behold, it worked. Both. The Core2Duo worked on the ECS with the old power source and the RAM that I used in the first place, and the Pentium D worked on my Gigabyte G31M-ES2L. What I discovered was that the Pentium D didn't receive power on the ECS, because I tried running it without the cooler and it remained at room temperature. On a side note, I also removed the HDDs just in case. So, in conclusion, any ideas? I can't return it, and I can still use it to upgrade another PC, but I would really prefer not to buy another CPU if possible.

  Read the article

• Whats the deal with python?

  - by gmatt

  My interests in programming lie mainly in algorithms, and lately I have seen many reputable researchers write a lot of their code in python. How easy and convenient is python for scientific computing? Does it have a library of algorithms that compares to matlab's? Is Python a scripting language or does it compile? Is it a great language for prototyping an algorithm? How long would it take me to learn enough of it to be productive provided I know C well and OO programming somewhat? Is it OO based? Sorry for the condensed format of questions, but I'm very curious and was hoping a more experienced programmer could help me out.

  Read the article

• How to use your computer to save the world?

  - by Francisco Garcia

  Sometimes I miss the "help other people" factor within computer-related fields. However, there are little things that we all can do to make this a better place—beyond trying to eradicate annoying stuff such as Visual Basic. You could join a cloud computing network such as World Community Grid to fight cancer, write a charityware application such as Vim, improve office IT infrastructure to support telecommuting and reduce CO2 emissions, use an ebook reader to save paper, ... What else can we do to help others? Which projects can have the biggest impact?

  Read the article

• Servers - Buying New vs Buying Second-hand

  - by Django Reinhardt

  We're currently in the process of adding additional servers to our website. We have a pretty simple topology planned: A Firewall/Router Server infront of a Web Application Server and Database Server. Here's a simple (and technically incorrect) diagram that I used in a previous question to illustrate what I mean: We're now wondering about the specs of our two new machines (the Web App and Firewall servers) and whether we can get away with buying a couple of old servers. (Note: Both machines will be running Windows Server 2008 R2.) We're not too concerned about our Firewall/Router server as we're pretty sure it won't be taxed too heavily, but we are interested in our Web App server. I realise that answering this type of question is really difficult without a ton of specifics on users, bandwidth, concurrent sessions, etc, etc., so I just want to focus on the general wisdom on buying old versus new. I had originally specced a new Dell PowerEdge R300 (1U Rack) for our company. In short, because we're going to be caching as much data as possible, I focussed on Processor Speed and Memory: Quad-Core Intel Xeon X3323 2.5Ghz (2x3M Cache) 1333Mhz FSB 16GB DDR2 667Mhz But when I was looking for a cheap second-hand machine for our Firewall/Router, I came across several machines that made our engineer ask a very reasonable question: If we stuck a boat load of RAM in this thing, wouldn't it do for the Web App Server and save us a ton of money in the process? For example, what about a second-hand machine with the following specs: 2x Dual-Core AMD Opteron 2218 2.6Ghz (2MB Cache) 1000Mhz HT 16GB DDR2 667Mhz Would it really be comparable with the more expensive (new) server above? Our engineer postulated that the reason companies upgrade their servers to newer processors is often because they want to reduce their power costs, and that a 2.6Ghz processor was still a 2.6Ghz processor, no matter when it was made. Benchmarks on various sites don't really support this theory, but I was wondering what server admin thought. Thanks for any advice.

  Read the article

• why don't more programming languages have builtin interfaces to the window manager?

  - by Naveen

  Programming is at the heart about automating tasks on a computer. Presumably those tasks would normally be done manually by a human. Humans use the computer through the keyboard, mouse, and interaction with the console or the window manager. But very few languages have built in functions that provide an interface to these basic computing objects. A notable exception is autohotkey, an open source language on windows, providing builtin functions that allow the following simple tasks: * Get Pixel Information * Get mouse position * Keyboard macros * Simulate key strokes * Simulate mouse click * Window management See examples on rosettacode. There have been various attempts on linux, many of which were stopped without explanation. One is the inactive tcl library: android. Search google code for android, lang:tcl

  Read the article

• Determine from where is "sh" being run under apache www-data user using using PF or NETSTAT

  - by Eugene van der Merwe

  I am working with a compromised Ubuntu 8.04 Plesk 9.5.4 server. It seems that a script on the server is continuously doing reverse lookups to random IPs on the Internet. I first spotted it during by using top and then noticed flashes of this coming up continuously: sh -c host -W 1 '198.204.241.10' I wrote a this script to interrogate ps every 1 second to see how frequently this script happens: #!/bin/bash while : do ps -ef | egrep -i "sh -c host" sleep 1 done The results are that this script runs often, every few seconds: www-data 17762 8332 1 10:07 ? 00:00:00 sh -c host -W 1 '59.58.139.134' www-data 17772 8332 1 10:07 ? 00:00:00 sh -c host -W 1 '59.58.139.134' www-data 17879 17869 0 10:07 ? 00:00:00 sh -c host -W 1 '198.204.241.10' www-data 17879 17869 1 10:07 ? 00:00:00 sh -c host -W 1 '198.204.241.10' www-data 17879 17869 0 10:07 ? 00:00:00 sh -c host -W 1 '198.204.241.10' root 18031 17756 0 10:07 pts/2 00:00:00 egrep -i sh -c host www-data 18078 16704 0 10:07 ? 00:00:00 sh -c host -W 1 '59.58.139.134' www-data 18125 17996 0 10:07 ? 00:00:00 sh -c host -W 1 '91.124.51.65' root 18131 17756 0 10:07 pts/2 00:00:00 egrep -i sh -c host www-data 18137 17869 0 10:07 ? 00:00:00 sh -c host -W 1 '198.204.241.10' www-data 18137 17869 1 10:07 ? 00:00:00 sh -c host -W 1 '198.204.241.10' My theory is if I can see who is launching the sh process or form where it's launched I can isolate the problem further. Can somebody please guide me using netstat or ps to identify from where sh is being run? I might get many suggestions that the OS is out of date and so the Plesk, but please bear in mind there are some very concrete reasons why this server is running legacy software. My question is aimed at a advanced Linux systems administrators who have in depth experience with security compromises and using netstat and ps to get to the bottom of it.

  Read the article

• Generating a beveled edge for a 2D polygon

  - by Metaphile

  I'm trying to programmatically generate beveled edges for geometric polygons. For example, given an array of 4 vertices defining a square, I want to generate something like this. But computing the vertices of the inner shape is baffling me. Simply creating a copy of the original shape and then scaling it down will not produce the desired result most of the time. My algorithm so far involves analyzing adjacent edges (triples of vertices; e.g., the bottom-left, top-left, and top-right vertices of a square). From there, I need to find the angle between them, and then create a vertex somewhere along that angle, depending on how deep I want the bevel to be. And because I don't have much of a math background, that's where I'm stuck. How do I find that center angle? Or is there a much simpler way of attacking this problem?

  Read the article

• VMware guest pauses when the host is idle - how do I keep it running?

  - by EMP

  I'm running VMWare Worstation 7 with Windows 7 x64 as guest, Windows XP x64 as host. Inside the guest I run a long-running console application, which prints out progress messages with timestamps on them. Sometimes I leave it running for several hours while I lock the host OS and don't touch the computer at all. When I come back I find that some time after I left it seems to have paused and automatically resumed: the console app hasn't made much progress and there's a large time gap in its progress messages. There's nothing relevant in the host event log, but in the guest Application event log I can see these messages around the time I left: A request to disable the Desktop Window Manager was made by process (VMware Tools Service) The Desktop Window Manager was unable to start because composition was disabled by a running application And later, around the time I returned, this shows up in the System log: The system time has changed to ?2012?-?01?-?12T06:36:46.921000000Z from ?2012?-?01?-?12T03:18:19.953079000Z. That seems to support my theory that it's VMware doing something and not Windows itself. The question is: how do I stop it doing that? I want my application to continue running. By the way, the power options are set to never sleep in both guest and host.

  Read the article

• Is it possible to to create a live linux iso containing a win xp virtual machine?

  - by mark

  I would like to have a Linux live system that contains a Windows xp virtual machine. This would be run from a bootable USB flash drive. My attempts so far have been unsuccessful. I created a Lubuntu 12.04 virtual machine with VMware. I updated and configured it to my needs, and installed Virtualbox. I then created a Windows xp vm with Virtualbox in the Lubuntu vm. I tested everything and everything worked, including USB devices. I installed Remastersys in the Lubuntu vm, copied the xp vm folder to the /etc/skel folder then created the custom iso with remastersys. I burned the iso and tested it on a laptop. It worked flawlessly. All programs and wireless networking worked. My problem was the xp vm. Virtualbox started fine but would not run the vm. I have the following error: Result Code: NS_ERROR_FAILURE (0x80004005) Component: VirtualBox Interface: IVirtualBox {c28be65f-1a8f-43b4-81f1-eb60cb516e66}. I ran remastersys again changing the permissions on the skel folder to R W for everyone. I also logged into Lubuntu as root and ran remastersys again. Each iso I created worked fine but would not start the xp vm inside. The last attempt virtualbox gave me an access error stating it can not access the virtual disk. Is what I want to do possible? In theory I don't see why it would not work. Is it a permissions issue? Should I create the iso then add the xp vm after by editing the iso by hand? Using a vm and not real hardware as a build machine a problem? Any ideas? keep any responses in laymens terms. I am still a Linux novice.

  Read the article

• Interrupting `while loop` with keyboard in Cython

  - by linello

  I want to be able to interrupt a long function with cython, using the usual CTRL+C interrupt command. My C++ long function is repeatedly called inside a while loop from Cython code, but I want to be able, during the loop, to send an "interrupt" and block the while loop. The interrupt also should wait the longFunction() to finish, so that no data are lost or kept in unknown status. This is one of my first implementation, which obviously doesn't work: computed=0; print "Computing long function..." while ( computed==0 ): try: computed = self.thisptr.aLongFunction() except (KeyboardInterrupt, SystemExit): computed=1 print '\n! Received keyboard interrupt.\n' break; (p.s. self.thisptr is the pointer to the current class which implements aLongFunction() )

  Read the article

• Perl: Fastest way to get directory (and subdirs) size on unix - using stat() at the moment

  - by ivicas

  I am using Perl stat() function to get the size of directory and it's subdirectories. I have a list of about 20 parent directories which have few thousand recursive subdirs and every subdir has few hundred records. Main computing part of script looks like this: sub getDirSize { my $dirSize = 0; my @dirContent = <*>; my $sizeOfFilesInDir = 0; foreach my $dirContent (@dirContent) { if (-f $dirContent) { my $size = (stat($dirContent))[7]; $dirSize += $size; } elsif (-d $dirContent) { $dirSize += getDirSize($dirContent); } } return $dirSize; } The script is executing for more than one hour and I want to make it faster. I was trying with the shell du command, but the output of du (transfered to bytes) is not accurate. And it is also quite time consuming. I am working on HP-UNIX 11i v1.

  Read the article

• Run Python script at startup using upstart

  - by MarcusMaximus

  I'm trying to create an upstart script to run a python script on startup. In theory it looks simple enough but I just can't seem to get it to work. I'm using a skeleton script I found here and altered. description "Used to start python script as a service" author "Me <[email protected]>" # Stanzas # # Stanzas control when and how a process is started and stopped # See a list of stanzas here: http://upstart.ubuntu.com/wiki/Stanzas#respawn # When to start the service start on runlevel [2345] # When to stop the service stop on runlevel [016] # Automatically restart process if crashed respawn # Essentially lets upstart know the process will detach itself to the background expect fork # Start the process script exec python /usr/local/scripts/script.py end script The test script I want it to run is currently a simple python script that runs without any issue when run from a terminal. #!/usr/bin/python2 import os, sys, time if __name__ == "__main__": for i in range (10000): message = "UpstartTest " , i , time.asctime() , " - Username: " , os.getenv("USERNAME") #print message time.sleep(60) out = open("/var/log/scripts/scriptlogfile", "a") print >> out, message out.close() The location/var/log/scripts has permissions 777 The file /usr/local/scripts/script.py has permissions 775 The upstart script /etc/init.d/pythonupstart.conf has permissions 755

  Read the article

• Binomial test in Python for very large numbers

  - by Morlock

  I need to do a binomial test in Python that allows calculation for 'n' numbers of the order of 10000. I have implemented a quick binomial_test function using scipy.misc.comb, however, it is pretty much limited around n = 1000, I guess because it reaches the biggest representable number while computing factorials or the combinatorial itself. Here is my function: from scipy.misc import comb def binomial_test(n, k): """Calculate binomial probability """ p = comb(n, k) * 0.5**k * 0.5**(n-k) return p How could I use a native python (or numpy, scipy...) function in order to calculate that binomial probability? If possible, I need scipy 0.7.2 compatible code. Many thanks!

  Read the article

• What is the risk of introducing non standard image machines to a corporate environment

  - by Troy Hunt

  I’m after some feedback from those in the managed desktop or network security space on the risks of introducing machines that are not built on a standard desktop image into a large corporate environment. This particular context relates to the standard corporate image (32 bit Win XP) in a large multi-national not being suitable for a particular segment of users. In short, I’m looking at what hurdles we might come across by proposing the introduction of machines which are built and maintained by a handful of software developers and not based on the corporate desktop image (proposing 64 bit Win 7). I suspect the barriers are primarily around virus definition updates, the rollout of service packs and patches and the compatibility of existing applications with the newer OS. In terms of viruses and software updates, if machines were using common virus protection software with automated updates and using Windows Update for service packs and patches, is there still a viable risk to the corporate environment? For that matter, are large corporate environments normally vulnerable to the introduction of a machine not based on a standard image? I’m trying to get my head around how real the risk of infection and other adverse events are from machines being plugged into the network. There are multiple scenarios outside of just the example above where this might happen (i.e. a vendor plugging in a machine for internet access during a presentation). Would a large corporate network normally be sufficiently hardened against such innocuous activity? I appreciate the theory as to why policies such as standard desktop images exist, I’m just interested in the actual, practical risk and how much a network should be protected by means other than what is managed on individual PCs.

  Read the article

• D-Link wireless router losing outbound data

  - by gsteinert

  I have a Linux box running the Apache web server behind a D-Link wireless router (nothing fancy, just standard kit that comes with Virgin Media broadband). My issue is that when requesting web pages (from within the network or via the web), the back end of the page seems to be being dropped. For example, I tried to display a text-only file, and all I could get was the first 40-70% of the file (it changed slightly with each refresh). The apache access logs show that only part of the data was being sent (~6000 bytes instead of the 12000+ bytes of the file). Removing my router from the equation fixes the issue and I can download any files no matter the size with no problems. My theory is that the uploaded packets are either being dropped or held up by the config of the router. Is there anything I can do to alleviate the problem? (Perhaps a way of reconfiguring the router to upload packets harder/better/faster/stronger or an option in apache that provides a workaround) As a last resort I will get a second NIC for my Linux box and turn it into a router, but that would mean the box will be on 24/7... not the most ideal of circumstances. Gary

  Read the article

• Force Installing a Radeon HD 2100 on Windows 8

  - by Click Ok

  I'm trying force installing a Radeon HD 2100 on Windows 8. I've found that link from AMD with the drivers for Windows7: http://support.amd.com/us/gpudownload/windows/legacy/Pages/legacy-radeonaiw-vista64.aspx I know too that AMD will stop support Radeon HD 400 and older: http://www.techspot.com/news/48321-amd-drops-windows-8-support-for-radeon-hd-4000-and-older.html Now, let's go to the problem. If I try install the 12.6 driver, Windows will stick with the "basic display adapter", and this is bad for 3d games like Minecraft, that runs really slow now compared with the previous Windows7 installation. Forcing install the catalyst driver can help to fix it. So, I follow that steps: Extract the Catalist Driver (C:\AMD\Support\12-6-legacy_vista_win7_64_dd_ccc_whql) Right click the "basic display adapter" on device manager, and "update driver" Search on PC I will choose the driver "With Disk" "C:\AMD\Support\12-6-legacy_vista_win7_64_dd_ccc_whql\Packages\Drivers\Display\W76A_INF" There is a big list of drivers and the nearest driver to HD 2100 is "Radeon HD 2350 Series" My questions: Why isn't "Radeon HD 2100 Series" listed? (or Where is it listed?) In theory it must be listed" The first link above show that "This article applies to the following configuration(s):" (...) "AMD Radeon HD 2000 Series" Am I doing something wrong?

  Read the article

• Providing access to a no-www website in an active directory environment

  - by oasisbob

  Our website is hosted externally, off our network. The canonical URL is a is intentionally lacking www, and will 301 redirect any requests containing www to the canonical URL. So far, so good. The problem is providing access to the website from within our LAN. In theory, the answer is simple: add a host record in DNS pointing foobarco.org to the external webhost. (eg foobarco.org -- 203.0.113.7) However, Our active directory domain is the same as our public website (foobarco.org), and AD appears to periodically auto-create host (A) records in the domain root corresponding to our domain controllers. This causes obvious problems: users on the LAN attempting to access the website resolve the domain controllers instead. As a stop-gap measure we're overriding DNS using the hosts file on clients, but this is a quick hack that doesn't scale well. The hosts-file hack hasn't broken anything obvious, so I doubt that this behavior is essential to AD operations, but I haven't found a way to disable it. Is it possible to override this behavior?

  Read the article

• How do I profile memory usage in my project

  - by Gacek

  Are there any good, free tools to profile memory usage in C# ? Details: I have a visualization project that uses quite large collections. I would like to check which parts of this project - on the data-processing side, or on the visualization side - use most of the memory, so I could optimize it. I know that when it comes to computing size of the collection the case is quite simple and I can do it on my own. But there are also certain elements for which I cannot estimate the memory usage so easily. The memory usage is quite big, for example processing a file of size 35 MB my program uses a little bit more than 250 MB of RAM.

  Read the article

• Faking a Single Address Space

  - by dsimcha

  I have a large scientific computing task that parallelizes very well with SMP, but at too fine grained a level to be easily parallelized via explicit message passing. I'd like to parallelize it across address spaces and physical machines. Is it feasible to create a scheduler that would parallelize already multithreaded code across multiple physical computers under the following conditions: The code is already multithreaded and can scale pretty well on SMP configurations. The fact that not all of the threads are running in the same address space or on the same physical machine must be transparent to the program, even if this comes at a significant performance penalty in some use cases. You may assume that all of the physical machines involved are running operating systems and CPU architectures that are binary compatible. Things like locks and atomic operations may be slow (having network latency to deal with and all) but must "just work".

  Read the article

• What to use to wait on a indeterminate number of tasks?

  - by Scott Chamberlain

  I am still fairly new to parallel computing so I am not too sure which tool to use for the job. I have a System.Threading.Tasks.Task that needs to wait for n number number of tasks to finish before starting. The tricky part is some of its dependencies may start after this task starts (You are guaranteed to never hit 0 dependent tasks until they are all done). Here is kind of what is happening Parent thread creates somewhere between 1 and (NUMBER_OF_CPU_CORES - 1) tasks. Parent thread creates task to be run when all of the worker tasks are finished. Parent thread creates a monitoring thread Monitoring thread may kill a worker task or spawn a new task depending on load. I can figure out everything up to step 4. How do I get the task from step 2 to wait to run until any new worker threads created in step 4 finish?

  Read the article

• Query about the service or technology behind gmail service

  - by user1726908

  I am a final year computer science student. I am studying in hyderabad, andhra pradesh, india. I have come to know that the gmail is a cloud service. I am very much interested in learning more about cloud computing. This technology has been puzzling,tickling,increasing my curiosity and i just want to learn as much as i can about it. And through experience, i have learnt that practically doing can improve our knowledge and thirst to learn more. Thus, I would like to know "what are the security measures which you have taken to keep the cloud service like gmail secure and authentic? What is the architecture of the service? What are the technologies used in building it? What are the different levels of security applied in general for building a private cloud?"

  Read the article

• How to interpret situations where Math.Acos() reports invalid input?

  - by Sean Ochoa

  Hey all. I'm computing the angle between two vectors, and sometimes Math.Acos() returns NaN when it's input is out of bounds (-1 input && input 1) for a cosine. What does that mean, exactly? Would someone be able to explain what's happening? Any help is appreciated! Here's me method: public double AngleBetween(vector b) { var dotProd = this.Dot(b); var lenProd = this.Len*b.Len; var divOperation = dotProd/lenProd; // http://msdn.microsoft.com/en-us/library/system.math.acos.aspx return Math.Acos(divOperation) * (180.0 / Math.PI); }

  Read the article

• Why are mainframes still around?

  - by ThaDon

  It's a question you've probably asked or been asked several times. What's so great about Mainframes? The answer you've probably been given is "they are fast" "normal computers can't process as many 'transactions' per second as they do". Jeese, I mean it's not like Google is running a bunch of Mainframes and look how many transactions/sec they do! The question here really is "why?". When I ask this question to the mainframe devs I know, they can't answer, they simply restate "It's fast". With the advent of Cloud Computing, I can't imagine mainframes being able to compete both cost-wise and mindshare-wise (aren't all the Cobol devs going to retire at some point, or will offshore just pickup the slack?). And yet, I know a few companies that still pump out net-new Cobol/Mainframe apps, even for things we could do easily in say .NET and Java. Anyone have a real good answer as to why "The Mainframe is faster", or can point me to some good articles relating to the topic?

  Read the article

• Mathematica & J/Link: Memory Constraints?

  - by D-Bug

  I am doing a computing-intensive benchmark using Mathematica and its J/Link Java interface. The benchmark grinds to a halt if a memory footprint of about 320 MB is reached, since this seems to be the limit and the garbage collector needs more and more time and will eventually fail. The Mathematica function ReinstallJava takes the argument command line. I tried to do ReinstallJava[CommandLine -> "java -Xmx2000m ..."] but Mathematica seems to ignore the -Xmx option completely. How can I set the -Xmx memory option for my java program? Where does the limit of 320 MB come from? Any help would be greatly appreciated.

  Read the article

< Previous Page | 97 98 99 100 101 102 103 104 105 106 107 108  | Next Page >